Hearing aid adapted for wireless power reception

ABSTRACT

A hearing aid system according to sonic examples includes a hearing aid which includes a microphone, amplifier, speaker, and a telecoil. In some examples, the hearing aid may include a battery or a capacitor for storing power wirelessly received from a distance separated wireless power transfer unit. The telecoil may be configured to receive audio signals and couple the audio signals to audio processing circuitry of the hearing aid. The telecoil may be further configured to receive power signals from the base unit and couple the power signals to power supply circuitry of the hearing aid, for example for charging the battery of the hearing aid. Examples of transmitter and receiver coils, and of distance and orientation optimization are described. Examples of wireless charging systems that may be used with hearing aids or other medical assistance devices are described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of pending U.S. patent applicationSer. No. 16/453,667 filed Jun. 26, 2019. The aforementioned applicationis incorporated herein by reference, in its entirety, for any purpose.

U.S. patent application Ser. No. 16/453,667 is a continuation of U.S.patent application Ser. No. 15/337,796 filed Oct. 28, 2016. Theaforementioned application is incorporated herein by reference, in itsentirety, for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/247,883 entitled “Mobile Wireless Power Transfer HearingSystem Aid System,” filed Oct. 29, 2015, and which provisionalapplication is hereby incorporated by reference in its entirety for anypurpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/249,051 entitled “Mobile Wireless Energy Transfer SystemComprising a Wire Wrapped Magnetic Material Core,” filed Oct. 30, 2015,and which provisional application is hereby incorporated by reference inits entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/252,645 entitled “Dual Purpose Receiving Coil for HearingAids,” filed Nov. 9, 2015, and which provisional application is herebyincorporated by reference in its entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/254,836 entitled “Dual Purpose Receiving Hearing AidCoil,” filed Nov. 13, 2015, and which provisional application is herebyincorporated by reference in its entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62,255,624 entitled “Advanced Mobile Wireless EnergyTransfer System Comprising a Wire Wrapped Magnetic Material Core,” filedNov. 16, 2015, and which provisional application is hereby incorporatedby reference in its entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/279,521 entitled “Wireless Power Charging With RemoteTransmitter,” filed Jan. 15, 2016, and which provisional application ishereby incorporated by reference in its entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/287,361 entitled “Safe Wireless Power Transfer forImplants,” filed Jan. 26, 2016, and which provisional application ishereby incorporated by reference in its entirety for any purpose.

U.S. patent application Ser. No. 15/337,796 claims the benefit under 35U.S.C. § 119(e) of the earlier filing date of U.S. ProvisionalApplication 62/293,975 entitled “Positioned Multiple Coil Transmitter,”filed Feb. 11, 2016, and which provisional application is herebyincorporated by reference in its entirety for any purpose.

TECHNICAL FIELD

Examples described herein relate to systems and methods for wirelesslypowering a hearing aid and/or charging a battery-powered hearing aid.

BACKGROUND

In many modern hearing aids, the space available within the hearing aiddevice is usually quite limited and designers of such products are loathto add more components to provide wireless power or charging to thehearing aid. This is particularly true for hearing aids placed withinthe ear canal, where space is a premium.

Normally, a hearing aid picks up sound with its microphone thenamplifies the sound for the wearer to hear that sound more clearly. Inmany modem hearing aids, a. telecoil is used as the input source insteadof (or in addition to) the microphone, such as to improve hearing aidfunction when a person is using a telephone with a dynamic speaker. Inthis manner, the hearing aid can pick up a magnetic signal whichrepresents sound produce by the speaker in the phone. In some cases, atelecoil is employed to bypass the microphone in the hearing aid toavoid a feedback between the microphone and the telephone speaker whenthe hearing aid wearer is speaking on a telephone. This is accomplishedby avoiding the sound from the speaker in the phone from being picked upby the microphone by muting the microphone circuit and instead using thetelecoil to pick up the magnetic field variations from the telephonespeaker and using that signal for the audio input of the hearing aidsystem.

SUMMARY

Examples of hearing aids and hearing aid systems are described herein.An example system may include a hearing aid and a base unit. The hearingaid may include a microphone configured to detect ambient sounds, andaudio processing circuitry including an amplifier operatively coupled tothe microphone to receive signals corresponding to the ambient soundsand amplify the signals, and a speaker configured to receive theamplified signals and generate an amplified sound corresponding to theamplified signal. The hearing aid may further include power supplycircuitry configured to power the microphone, the amplifier, and thespeaker, a receiver operatively coupled to the audio processingcircuitry and the power supply circuitry, wherein the receiver comprisesat least one receiving coil configured to receive radiofrequency (RF)signals, and a switching circuit configured to generate first signalsresponsive to RF signals in a first frequency range and couple the firstsignals to the audio processing circuitry and further configured togenerate second signals responsive to RF signals in a second frequencyrange and couple the second signals to the power supply circuitry. Insome examples, the at least one receiving coil may include a telecoil, acommunication coil, or a combination of the two. In some examples,either one of the telecoil and the communication coil may be configuredto receive signals for wireless power reception in addition to otherfunctionality provided by the coils (e.g., audio reception, datareception, etc.)

In yet further examples, a hearing aid may include a microphoneconfigured to detect ambient sounds, and audio processing circuitryincluding an amplifier operatively coupled to the microphone to receivesignals corresponding to the ambient sounds and amplify the signals, anda speaker configured to receive the amplified signals and generate anamplified sound corresponding to the amplified signal. The hearing aidmay include power supply circuitry configured to power the microphone,the amplifier, and the speaker. The hearing aid may further include, areceiver operatively coupled to the audio processing circuitry and thepower supply circuitry, wherein the receiver comprises a receiving coilconfigured to receive radiofrequency (RF) signals, wherein the receivingcoil comprises a magnetic metal core, a first winding connected to theaudio processing circuitry, and a second winding connected to the powersupply circuitry, wherein the first winding is configured to tune thereceiving coil to receive signals in a first frequency range and thesecond winding is configured to tune the receiving coil to receivesignals in a second higher frequency range.

In some examples, the base unit may include a transmitter configured totransmit radio signals in the second frequency range. Signalstransmitted from the base unit in the second frequency range may be usedto power and/or recharge the hearing aid.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects and attendant advantages of the present invention willbecome apparent from the following detailed description of variousembodiments, including the best mode presently contemplated ofpracticing the invention, when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a block diagram of a system according to examples ofthe present disclosure;

FIG. 2 illustrates examples of electronic devices attached to eyewear inaccordance with the present disclosure;

FIG. 3 illustrates an example of a receiving coil for an electronicdevice and a transmitting coil for a base unit in accordance with thepresent disclosure;

FIG. 4 illustrates a block diagram of a mobile base unit implemented ina mobile phone case form factor according to examples of the presentdisclosure;

FIGS. 5A and 5B illustrate isometric and exploded isometric views of abase unit implemented as a mobile phone case according to examples ofthe present disclosure;

FIG. 6 illustrates a flow chart of a process according to some examplesherein;

FIG. 7 illustrates a flow chart of a process according to furtherexamples herein;

FIG. 8 illustrates a typical use scenario of a base unit incorporatedinto or attached to a mobile phone;

FIGS. 9A-9E illustrate views of a base unit according to some examplesof the present disclosure;

FIG. 10A-10C illustrate views of a base unit implemented in the form ofa case for a communication device, such as a tablet;

FIGS. 11A-11D illustrate views of a base unit implemented as a partialcase for a communication device;

FIGS. 12A and 12B illustrate views of a base unit implemented as apartial case with movable cover configured for coupling to acommunication device;

FIG. 13 illustrates an exploded isometric view of a base unit accordingto further examples of the present disclosure;

FIGS. 14A-14C illustrate views of the base unit in FIG. 13;

FIGS. 15A-15C illustrate arrangements of transmitting coils of baseunits according to examples of the present disclosure;

FIGS. 16A-16C illustrate arrangements of transmitting coils of baseunits according to further examples of the present disclosure;

FIG. 17 illustrates a base unit in the form of a puck in accordance withfurther examples herein;

FIG. 18 illustrates an example transmitter and receiver configuration inaccordance with the present disclosure;

FIG. 19 illustrates simulation results of wireless power transfersystems according to some examples of the present disclosure;

FIG. 20 illustrates simulation results of wireless power transfersystems according to further examples of the present disclosure;

FIG. 21 illustrates a comparison between wireless power transfer systemsaccording to some examples of the present disclosure and Qi standardsystems; and

FIG. 22 illustrates magnetic field lines of inductively coupledtransmitting and receiving coils in accordance with some examplesherein.

FIG. 23 is a schematic illustration of a system in accordance withexamples described herein.

FIG. 24 is a schematic illustration of a band that may include arepeater and/or wearable electronic device in accordance with examplesdescribed herein.

FIG. 25 is a flowchart illustrating a method arranged in accordance withexamples described herein.

FIG. 26 is a schematic illustration of a system arranged in accordancewith examples described herein.

FIG. 27 is a schematic illustration of four transmitter designs arrangedin accordance with examples described herein.

FIG. 28 is a schematic illustration of a base unit system and across-sectional view of the base unit system in accordance with examplesdescribed herein.

FIG. 29 is a schematic illustration of a variety of transmitter andreceiver arrangements in accordance with examples described herein.

FIG. 30 is a schematic illustration of transmitter placement in a jacketin accordance with examples described herein.

FIG. 31 is a schematic illustration of driving sequences that may beused to drive the transmitter designs shown in the example of FIG. 27arranged in accordance with examples described herein.

FIG. 32 is a schematic illustration of a hearing aid arranged inaccordance with examples described herein.

FIG. 33 is a circuit diagram of a high pass filter in accordance withexamples described herein.

FIG. 34 is a schematic illustration of a wireless charging systemincluding a hearing aid and at least one base unit in accordance withexamples described herein.

FIG. 35A is a schematic illustration of another wireless charging systemincluding a hearing aid and at least one base unit in accordance withexamples described herein.

FIG. 35B is a schematic illustration of yet another wireless chargingsystem including a hearing aid and at least one base unit in accordancewith examples described herein.

FIG. 36 is a schematic illustration of a wirelessly powered implantabledevice arranged in accordance with examples described herein.

FIG. 37 is a schematic illustration of another hearing aid in accordancewith examples described herein.

FIG. 38 is a schematic illustration of some of the components of yetanother hearing aid in accordance with examples described herein.

DETAILED DESCRIPTION

Systems, methods and apparatuses for wirelessly powering electronicdevices, for example a hearing aid, are described. Systems and methodsin accordance with the examples herein may provide wireless power atgreater distance separation between the power transmitting and receivingcoils than commercially available systems. Additional advantages may beimproved thermal stability and orientation freedom, as will be describedfurther below.

According to some examples herein, a wireless power transfer system, andmore specifically a weakly resonant system with relatively broadresonance amplification with moderate frequency dependence, isdescribed. In accordance with some examples herein, dependence on therelative sizes of the inductive coils and orientation between the coilsmay be reduced as compared to such dependence on coil sizes andorientation typically found in commercially available systems withstrong resonant coupling at Q factors exceeding 100. In some examplesaccording to the present disclosure, wireless power transfer systems mayoperate at Q value less than 100. Unlike commercially available systems,which typically use air core coils, according to some examples herein,the shape of the magnetic field between the coils may be augmented, forexample by using a medium with high permeability such as ferrite.According to some examples, guided flux or partially guided flux may beused to improve the performance of the system in a given orientation. Anappropriate frequency, for example a body safe frequency, is used forpower broadcast. The broadcast frequency may be tuned to reduce lossesthat may result from shielding effects.

FIG. 1 shows a block diagram of a system for wirelessly powering one ormore electronic devices according to some examples of the presentdisclosure. The system 10 includes a base unit 100 and one or moreelectronic devices 200. The base unit 100 is configured to wirelesslyprovide power to one or more of the electronic devices 200, which may beseparated from the base unit by a distance. In some examples, thedistance may be 0.5 mm, 1 mm, 2 mm, 5 mm, 10 mm, 20 mm, 30 mm, 50 mm orgreater. The base unit 100 is configured. to provide power wirelessly toan electronic device 200 while the electronic device remains within athreshold distance (e.g., a charging range or charging zone 106) of thebase unit 100. The base unit 100 may be configured to selectivelytransmit power wirelessly to any number of electronic devices (e.g., 1,2, 3, 4, 5, 6, 7, 8, 9, or 10 although a greater number than 10 devicesmay be charged in some examples) detected to be within a proximity(e.g., within the charging range) of the base unit 100. Although theelectronic device 200 may typically be charged (e.g., coupled to thebase unit for charging) while being distance-separated from the baseunit 100, it is envisioned and within the scope of this disclosure thatthe base unit 100 may operate to provide power wirelessly to anelectronic device 200 when the electronic device 200 is adjacent to orin contact with the base unit 100. In some examples, the base unit maybe mechanically disconnected or decoupled from the electronic device towhich the base unit is capable of transmitting power. That is, in someexamples, the base unit is movable with respect to the electronic devicewhile the base unit is transmitting power to the electronic device.

The base unit 100 may include a transmitter 110, a battery 120, and acontroller 130. The transmitter 110 includes at least one transmittingcoil 112 (interchangeably referred to as Tx coil). The transmitting coil112 may include a magnetic core with conductive windings, The windingsmay include copper wire (also referred to as copper windings). In someexamples, the copper wire may be monolithic copper wire (e.g.,single-strand wire). In some examples, the copper wire may bemulti-strand copper wire (e.g., Litz wire), which may reduce resistivitydue to skin effect in some examples, which may allow for higher transmitpower because resistive losses may be lower. In some examples, themagnetic core may be a ferrite core (interchangeably referred to asferrite rod). The ferrite core may comprise a medium permeabilityferrite, for example 78 material supplied by Fair-Rite Corporation. Insome examples, the ferrite core may comprise a high permeabilitymaterial, such as Vitroperm 500F supplied by Vacuumschmelze in Germany.Ferrite cores comprising other ferrite materials may be used. In someexamples, the ferrite may have a medium permeability of micro-i (μ) ofabout 2300. In some examples, the ferrite may have permeability ofmicro-i (μ) ranging from about 200 to about 5000. In some examples,different magnetic material may be used for the magnetic core.Generally, transmitting coils described herein may utilize magneticcores which may in some examples shape the field provided by thetransmitting coil, as the field lines preferentially go through themagnetic core, in this manner, partially guided flux may be used where aportion of the flux is guided by the magnetic core.

The transmitting coil 112 may be configured to inductively couple to areceiving coil 210 in the electronic device 200. In this manner, powermay be transmitted from the transmitting coil. 112 to the receiving coil210 (e.g. through inductive coupling). In some examples, the transmitter110 may be additionally configured as a receiver and may thus beinterchangeably referred to as transmitter/receiver. For example, thetransmitting coil of the transmitter/receiver may additionally beconfigured as a receiving coil. In some examples, thetransmitter/receiver may additionally include a receiving coil. In yetfurther examples, the base unit may include a separate receiver 140comprising a receiving coil. The transmitter/receiver or separatereceiver of the base unit may be configured. to wirelessly receive power(102) and/or data (104) as will be further described below.

In some examples, the transmitter 110 may include a single transmittingcoil 112.

The transmitting coil 112 may be placed in an optimal location and/ororientation to provide an optimum charging zone 106. In some examples,the transmitting coil may be placed in a location within the base unitselected to provide a large number of charging opportunities during atypical use of the device. For example, the transmitting coil 112 may beplaced near a side of the base unit which most frequently comes inproximity to an electronic device (e.g., a top side of a base unitimplemented as a mobile phone case as illustrated in the example in FIG.6).

In some examples, the transmitter 110 includes a plurality oftransmitting coils 112. The transmitting coils 112 may be arranged invirtually any pattern. For example, the base unit may include a pair ofcoils which are angled to one another. In some examples, the coils maybe arranged at angles smaller than 90 degrees, for example rangingbetween 15-75 degrees. In some examples, the coils may be arranged at 45degrees relative to one another. Other combinations and arrangements maybe used, examples of some of which will be further described below.

In some examples, the transmitting coils may be arranged to provide anearly omnidirectional charging zone 106 (also referred to as chargingsphere or hotspot). The charging zone 106 of the base unit may bedefined by a three dimensional space around the base unit which extendsa threshold distance from the base unit in all three directions (e.g.,the x. y, and z directions). Although a three dimensions (3D) spacecorresponding to a charging range of the base unit may be referred toherein as a sphere, it will be understood that the three dimensions (3D)space corresponding to a charging range need not be strictly sphericalin shape. In sonic examples, the charging sphere may be an ellipsoid ora different shape.

Efficiency of wireless power transfer within the charging zone 106 maybe variable, for example, depending on a particular combination oftransmitting and receiving coils and/or a particular arrangement of thecoils or relative arrangements of the coils in the base unit andelectronic device(s). The one or more transmitting coils 112 may bearranged within a housing of the base unit in a manner which improvesthe omni-directionality of the charging zone 106 and/or improves theefficiency of power transmission within the zone 106. In some examples,one or more transmitting coils 112 may be arranged within the housing ina manner which increases the opportunities for charging during typicaluse of the base unit. For example, the transmitting coil(s) may extend,at least partially, along one or more sides of the base unit which aremost brought near an electronic device (e.g., the top or sides of amobile phone case base unit which may frequently be moved in proximitywith a wearable electronic device such as eyewear camera or a digitalwrist watch). In some examples, the base unit may be placed on a surface(e.g., a table or desk) during typical use and electronic devices may beplaced around the base unit. In such examples, the transmitting coil(s)may be arranged along a perimeter of the base unit housing.

In some examples, the base unit may be attached to a mobile phone via anattachment mechanism such as adhesive attachment, an elastic attachment,a spring clamp, suction cup(s), mechanical pressure, or others. In someexamples, the base unit may be enclosed or embedded in an enclosure(also referred to as housing), which may have a generally planar shape(e.g., a rectangular plate). An attachment mechanism may be coupled tothe housing such that the base unit may be removably attached to amobile phone, a table, or other communication device. In an example, theattachment mechanism may be a biasing member, such as a clip, which isconfigured to bias the mobile phone towards the base unit in the formof, by way of example only, a rectangular plate. For example, a clip maybe provided proximate a side of the base unit and the base unit may beattached to (e.g., clipped to) the mobile phone via the clip in a mannersimilar to attaching paper or a notebook/notepad to a clip board. Insome examples, the base unit may be adhesively or elastically attachedto the communication device and/or to a case of the communicationdevice.

In further examples, the base unit may be separate from thecommunication device. In yet further examples, the base unit may beincorporated into (e.g., integrated into) the communication device. Forexample, the transmitter 110 may be integrated with other components ofa typical mobile phone. The controller 130 may be a separate IC in themobile phone or its functionality may be incorporated into the processorand/or other circuitry of the mobile phone. Typical mobile phonesinclude a rechargeable battery which may also function as the battery120 of the base unit. In this manner, a mobile phone may be configuredto provide power wirelessly to electronic devices, such as a separatedelectronic wearable devices.

As previously noted, the base unit 100 may include a battery 120. Thebattery 120 may be a rechargeable battery, such as a Nickel-MetalHydride (NiMH), a Lithium ion (Li-ion), or a Lithium ion polymer (Li-ionpolymer) battery. The battery 120 may be coupled to other components toreceive power. For example, the battery 120 may be coupled to an energygenerator 150. The energy generator 150 may include an energy harvestingdevice which may provide harvested energy to the battery for storage anduse in charging the electronic device(s). Energy harvesting devices mayinclude, but not be limited to, kinetic-enemy harvesting devices, solarcells, thermoelectric generators, or radio-frequency harvesting devices.In some examples, the battery 120 may be coupled to an input/outputconnector 180 such as a universal serial bus (USB) port. It will beunderstood that the term USB port herein includes any type of USBinterface currently known or later developed, for example mini and microUSB type interfaces. Other types of connectors, currently known or laterdeveloped, may additionally or alternatively be used. The I/O connector180 (e.g., USB port) may be used to connect the base unit 100 to anexternal device, for example an external power source or a computingdevice (e.g., a personal computer, laptop, tablet, or a mobile phone).

The transmitter 110 may be operatively coupled to the battery 120 toselectively receive power from the battery and wirelessly transmit thepower to the electronic device 200. As described herein, in someexamples, the transmitter may combine the functionality of transmitterand receiver. In such examples, the transmitter may also be configuredto wirelessly receive power from an external power source. In someexamples, the base unit may be an intermediate base unit, which mayinclude a capacitor (e.g., a supercapacitor) in addition to or insteadof a battery. The intermediate base unit may be configured to store asmall amount of power received e.g., from another base unit which isthen rebroadcast to be received by an electronic device in proximity. Inthis regard, the intermediate base unit may act as an intermediarycomponent or a repeater which may increase the charging zone of a mainbase unit. In some examples, the base unit may be configured such thatduring transmission of power from the base unit, power may be wirelesslyreceived by any electronic devices within proximity (e.g., within thebroadcast distance of the transmitter).

The transmitter 110 may be weakly-coupled to a receiver in theelectronic device 200 in some examples. There may not be a tightcoupling between the transmitter 110 and the receiver in the electronicdevice 200. Highly resonant coupling may be considered tight coupling.The weak (or loose) coupling may allow for power transmission over adistance (e.g. from a base unit in or on a mobile phone to a wearabledevice on eyewear or from a base unit placed on a surface to a wearabledevice placed on the surface in a neighborhood of, but not on, the baseunit). So, for example, the transmitter 110 may be distance separatedfrom the receiver. The distance may be greater than 1 mm in someexamples, greater than 10 mm in some examples, greater than 100 mm insome examples, and greater than 1000 mm in some examples. Otherdistances may be used in other examples, and power may be transferredover these distances.

The transmitter 110 and the receiver in the electronic device 200 mayinclude impedance matching circuits each having an inductance,capacitance, and resistance. The impedance matching circuits mayfunction to adjust impedance of the transmitter 110 to better matchimpedance of a. receiver under normal expected loads, although inexamples described herein the transmitter and receiver may have transmitand receive coils, respectively, with different sizes and/or othercharacteristics such that the impedance of the receiver and transmittermay not be matched by the impedance matching circuits, but the impedancematching circuits may reduce a difference in impedance of thetransmitter and receiver. The transmitter 110 may generally provide awireless power signal which may be provided at a body-safe frequency,e.g. less than 500 kHz in some examples, less than 300 kHz in someexamples, less than 200 kHz in some examples, less than 125 kHz in someexamples, less than 100 kHz in some examples, although other frequenciesmay be used. It may be desirable to utilize a frequency which is notregulated, or not heavily regulated. For example, a frequency less than300 kHz in some examples.

Transmission/broadcasting of power may be selective in that a controllercontrols

When power is being broadcast. The base unit may include a controller130 coupled to the battery 120 and transmitter 110. The controller 130may be configured to cause the transmitter 110 to selectively transmitpower, as will be further described. A charger circuit may be connectedto the battery 120 to protect the battery from overcharging. The Chargercircuit may monitor a level of charge in the battery 120 and turn offcharging when it detects that the battery 120 is fully charged. Thefunctionality of the charger circuit may, in some examples, beincorporated within the controller 130 or it may be a separated circuit(e.g., separate IC chip).

In some examples, the base unit may include a memory 160. The memory 160may be coupled to the transmitter 110 and/or any additional transmittersand/or receivers (e.g., receiver 140) for storage of data transmitted toand from the base unit 100. For example, the base unit 100 may beconfigured. to communicate data, such as image data, wirelessly to andfrom the electronic device 200, e.g., receive images acquired with anelectronic device in the form of a wearable camera, or transmitconfiguration data to the electronic device. In some examples, the datamay include configuration parameters for or associated with theelectronic device. For example, the base unit may be configured toreceive and transmit to the electronic device (e.g., a hearing aid)parameters or settings for configuring the hearing aid or controllingoperation of the hearing aid. In some examples, the base unit may beconfigured to receive data from the hearing aid. In some examples, thememory 160 may be integrated within the transmitter. In some examples,the memory may be a buffer which only temporarily stores data receivedfrom one electronic device before it is retransmitted to anotherelectronic device. The base unit may include one or more sensors 170,which may be operatively coupled to the controller. A sensor 170 maydetect a status of the base unit such that the transmitter may providepower selectively and/or adjustably under control from controller 130.

The electronic device 200 may be configured to provide virtually anyfunctionality, for example an electronic device configured as a wearablecamera, an image display, an audio system, a hearing aid, or any smartdevice. In addition to circuitry adapted to perform the specificfunction of the electronic device, the electronic device 200 may furtherinclude circuitry associated with wireless charging. The electronicdevice 200 may include at least one receiving coil 212, which may beconfigured to receive power from the base unit. In some examples, thereceiving coil 212 may be operatively coupled to a rechargeable powercell onboard the electronic device 200 such that the electronic device200 may be wirelessly recharged by the base unit. In other examples, theelectronic device 200 may not include a battery and may instead beconfigured to be powered wirelessly by a base unit in proximity. In someexamples, the receiving coil 212 of such electronic device may beoperatively coupled to a capacitor to receive and temporarily storepower for operation of the electronic device 200 until the electronicdevice can again be positioned in proximity of a base unit.

Frequent charging in a manner that is non-invasive or minimally invasiveto the user during typical use of the electronic device may be achievedvia wireless coupling between the receiving and transmitting coils inaccordance with the examples herein. In some examples, the electronicdevice may be a wearable electronic device, which may interchangeably bereferred to herein as electronic wearable devices. The electronic devicemay have a sufficiently small form factor to make it easily portable bya user. The electronic device 200 may be attachable to clothing or anaccessory worn by the user, for example eyewear. For example, theelectronic device 200 (e.g., a hearing aid) may be attached to eyewearusing a guide 6 (e.g., track) incorporated in or attached to theeyewear, e.g., as illustrated in FIG. 2 (only a portion of eyewear,namely the temple, is illustrated so as not to clutter the drawing).

In some examples, the base unit may additionally be configured as abooster for RF energy—e.g. way of example only, examples of base unitsdescribed herein may include components that may boost RF energy such asthat of Wi-Fi, Bluetooth, ZigBee, or other signals coming from, e.g. asmart phone or mobile communication system that may be inserted intoand/or positioned near base units described herein. For example, thebase unit may include a transceiver circuit that may pick up the RFenergy, by way of example only, one of a; WIFI, Bluetooth, ZigBee signalgenerated by the smart phone or mobile communication system andrebroadcast the signal at higher power levels to be, for example, pickedup by a wearable electronic device. This rebroadcast can be implementedusing, for example, a unidirectional antenna that predominatelybroadcast the energy in a direction away from the user's head when theyare talking on the smart phone or mobile communication system. In someexamples, a boost circuit in the base unit may increase power whenwearable devices are detected by the base unit or by an applicationrunning on the smart phone or mobile communication system. In someexamples controls could reside in the application running on the smartphone or mobile communication system. In addition to boosting power forenergy transfer, data signals may also be amplified to improve datatransfer between a wearable device and the smart phone or mobilecommunication system.

In some examples, the base unit may generate an RF signal with an RFgenerating circuit included the base unit. For example, the RF signalmay be generated at a frequency consistent with a receiver in an energyharvesting circuit of a wearable device. Such a RF generatingtransmitter in the base unit maybe turned on, for example, by a signalfrom a communication system or other electronic device when, for examplethe communication system or other electronic device receives a messagefrom a wearable device or other indicator that the wearable device mayrequire additional energy that is not available from the environment toproduce adequate charging current for a battery or capacitor in thewearable device.

FIG. 2 shows examples of electronic devices 200 which may be configuredto receive power wirelessly in accordance with the present disclosure.In some examples, the electronic device may be a camera or any othertype of an electronic system attached to eyewear, such as an imagedisplay system, an air quality sensor, a UV/HEV sensor, a pedometer, anight light, a blue tooth enabled communication device such as bluetooth headset or another type of audio system. In some examples, theelectronic device may be worn elsewhere on the body, for example aroundthe wrist (e.g., an electronic watch or a biometric device, such as apedometer). In some examples, the electronic device may be at a hearingaid worn inside (e.g., a canal hearing device) or partially inside theear (e.g., a behind-the-ear device). In some examples, the electronicdevice may be at least partially internal to the body, for example inthe case of an implantable device (e.g., an implanted hearing aid suchas COCHLEAR or the like). The electronic device 200 may be another typeof electronic device other than the specific examples illustrated. Theelectronic device 200 may be virtually any miniaturized electronicdevice, for example and without limitation a camera, image capturedevice, IR camera, still camera, video camera, image sensor, repeater,resonator, sensor, sound amplifier, directional microphone, eyewearsupporting an electronic component, spectrometer, directionalmicrophone, microphone, camera system, infrared vision system, nightvision aid, night light, illumination system, sensor, pedometer,wireless cell phone, mobile phone, wireless communication system,projector, laser, holographic device, holographic system, display,radio, GPS, data storage, memory storage, power source, speaker, falldetector, alertness monitor, geo-location, pulse detection, gaming, eyetracking, pupil monitoring, alarm, CO sensor, CO detector, CO2 sensor,CO2 detector, air particulate sensor, air particulate meter, UV sensor,UV meter, IR sensor, IR meter, thermal sensor, thermal meter, poor airsensor, poor air monitor, bad breath sensor, bad breath monitor, alcoholsensor, alcohol monitor, motion sensor, motion monitor, thermometer,smoke sensor, smoke detector, pill reminder, audio playback device,audio recorder, speaker, acoustic amplification device, acousticcanceling device, assisted hearing assisted device, informationalearbuds, smart earbuds, smart ear-wearables, video playback device,video recorder device, image sensor, fall detector, alertness sensor,alertness monitor, information alert monitor, health sensor, healthmonitor, fitness sensor, fitness monitor, physiology sensor, physiologymonitor, mood sensor, mood monitor, stress monitor, pedometer, motiondetector, geo-location, pulse detection, wireless communication device,gaming device, eyewear comprising an electronic component, augmentedreality system, virtual reality system, eye tracking device, pupilsensor, pupil monitor, automated reminder, light, alarm, cell phonedevice, phone, mobile communication device, poor air quality alertdevice, sleep detector, doziness detector, alcohol detector,thermometer, refractive error measurement device, wave front measurementdevice, aberrometer, GPS system, smoke detector, pill reminder, speaker,kinetic energy source, microphone, projector, virtual keyboard, facerecognition device, voice recognition device, sound recognition system,radioactive detector, radiation detector, radon detector, moisturedetector, humidity detector, atmospheric pressure indicator, loudnessindicator, noise indicator, acoustic sensor, range finder, laser system,topography sensor, motor, micro motor, nano motor, switch, battery,dynamo, thermal power source, fuel cell, solar cell, kinetic energysource, thermo electric power source, smart band, smart watch, smartearring, smart necklace, smart clothing, smart belt, smart ring, smartbra, smart shoes, smart footwear, smart gloves, smart hat, smartheadwear, smart eyewear, and other such smart devices. In some examples,the electronic device 200 may be a smart device. In some examples, theelectronic device 200 may be a micro wearable device or an implanteddevice.

The electronic device 200 may include a receiver (e.g., Rx coil 212)configured to receive power wirelessly, such as power broadcast by thetransmitter (e.g. Tx coil 112) of the base unit 100. The receiver may beconfigured to automatically receive power from the base unit when theelectronic device and thus the receiver is within proximity of the baseunit (e.g., when the electronic device is a predetermined distance, orwithin a charging range, from the base unit). The electronic device 200may store excess power in a power cell onboard the electronic device.The power cell onboard the electronic device may be significantlysmaller than the battery of the base unit. Frequent recharging of thepower cell may be effected by virtue of the electronic device frequentlycoming within proximity of the base unit during normal use. For example,in the case of a wearable electronic device coupled to eyewear and abase unit in the form of a cell phone case, during normal use, the cellphone may be frequently brought to proximity of the user's head toconduct phone calls during which times recharging of the power cellonboard the wearable electronic device may be achieved. In someexamples, the wearable electronic device may have limited or no energystorage capability and an intermediate component may be provided inproximity to receive and store the power from the base unit andretransmit the power to the wearable electronic device while the deviceis worn. In some examples in which the wearable electronic device is ahearing aid, an intermediate base unit may be located in proximity tothe hearing aid, such as attached to a user's eyewear or to a user'sbody part (e.g., on the ear, on a necklace, belt, armband, neck band,headband, etc.) to receive and retransmit power from a main base unit.As described a main base unit may be portable and carried by the user(such as by virtue of being attached to a user's cell phone) and thustypically in proximity to a wearable electronic device or intermediatebase unit to provide frequent opportunity for powering or charging anelectronic device. In some examples, the electronic device may includean energy harvesting system.

As described, in some examples, the electronic device 200 may notinclude a battery and may instead be directly powered by wireless powerreceived from the base unit 100. In some examples, the electronic device200 may include a capacitor (e.g., a supercapacitor or anultracapacitor) operatively coupled to the Rx coil 212.

Typically in existing systems which apply wireless power transfer,transmitting and receiving coils may have the same or substantially thesame coil ratios. However, given the smaller form factor of miniaturizedelectronic devices according to the present disclosure, suchimplementation may not be practical. In some examples herein, thereceiving coil may be significantly smaller than the transmitting coils,e.g., as illustrated in FIG. 3. In some examples, the Tx coil 112 mayhave a dimension (e.g., a length of the wire forming the windings 116, adiameter of the wire forming the windings 116, a diameter of the coil112, a number of windings 116, a length of the core 117, a diameter ofthe core 117, a surface area of the core 117) which is greater, forexample twice or more, than a respective dimension of the Rx coil 212(e.g., a length of the wire forming the windings 216, a diameter of thecoil 212, a number of windings 216, a. length of the core 217, a surfacearea of the core 217). In some examples, a dimension of the Tx coil 112may be two times or greater, five times or greater, 10 times or greater,20 times or greater, or 50 times or greater than a respective dimensionof the Rx coil 212. In some examples, a dimension of the Tx coil 112 maybe up to 100 times a respective dimension of the Rx coil 212. Forexample, the receiving coil 212 (Rx coil) may comprise conductive wirehaving wire diameter of about 0.2 mm. The wire may be a single strandwire. The Rx coil in this example may have a diameter of about 2.4 mmand a length of about 13 mm, The Rx coil may include a ferrite rodhaving a diameter of about 1.5 mm and a length of about 15 mm. Thenumber of windings in the Rx coil may be, by way of example only,approximately 130 windings. The transmitting coil 112 (Tx coil) maycomprise a conductive wire having a wire diameter of about 1.7 mm. Thewire may be a multi-strand wire. The Tx coil in this example may have adiameter of about 14.5 mm and a length of about 67 mm. The Tx coil mayinclude a ferrite rod having a diameter of about 8 mm and a length ofabout 68 mm. Approximately 74 windings may be used for the Tx coil.Other combinations may be used for the Tx and Rx coils in otherexamples, e.g., to optimize power transfer efficiency even at distancesin excess of approximately 30 cm or more. In sonic examples, thetransfer distance may exceed 12 inches. In some examples herein, the Txand Rx coils may not be impedance matched, as may be typical inconventional wireless power transfer systems. Thus, in some examples,the Tx and Rx coils of the base unit and electronic device,respectively, may be referred to as being loosely-coupled. According tosome examples, the base unit is configured for low Q factor wirelesspower transfer. For example, the base unit may be configured forwireless power transfer at Q factors less than 500 in some examples,less than 250 in some examples, less than 100 in some examples, lessthan 80 in some examples, less than 60 in some examples, and other Qfactors may be used. While impedance matching is not required, examplesin which the coils are at least partially impedance matched are alsoenvisioned and within the scope of this disclosure. While the Tx and Rxcoils in wireless powers transfer systems described herein may betypically loosely coupled, the present disclosure does not excludeexamples in which the Tx and. Rx coils are impedance matched.

The receiving coil (e.g., Rx coil 212) may include conductive windings,for example copper windings. Conductive materials other than copper maybe used. In some examples, the windings may include monolithic (e.g.,single-strand) or multi-strand wire. In some examples, the core may be amagnetic core which includes a magnetic material such as ferrite. Thecore may be shaped in the form of a rod. The Rx coil may have adimension that is smaller than a dimension of the Tx coil, for example adiameter, a length, a surface area, and/or a mass of the core (e.g.,rod) may be smaller than a diameter, a length, a surface area, and/or amass of the core (e.g., rod) of the Tx coil. In some examples, themagnetic core (e.g., ferrite rod) of the Tx coil may have a surface areathat is two greater or more than a surface area of the magnetic core(e.g., ferrite rod) of the Rx coil. In some examples, the Tx coil mayinclude a larger number of windings and/or a greater length of wire inthe windings when unwound than the number or length of wire of thewindings of the Rx coil. In some examples, the length of unwound wire ofthe Tx coil may be at least two times the length of unwound wire of theRx coil.

In some examples, an Rx coil 212 may have a length from about 10 mm toabout 90 mm and a radius from about 1 mm to about 15 mm. In one example,the performance of an Rx coil 212 having a ferrite rod 20 mm in lengthand 2.5 mm in diameter with 150 conductive windings wound thereupon wassimulated with a Tx coil 112 configured to broadcast power at frequencyof about 125 KHz. The Tx coil 112 included a ferrite rod having a lengthof approximately 67.5 mm and a diameter of approximately 12 mm. Theperformance of the coils was simulated in an aligned orientation inwhich the coils were coaxial and in a parallel orientation in which theaxes of the coils were parallel to one another, and example results ofsimulations performed are shown in FIGS. 21 and 22. Up to 20%transmission efficiency was obtained in the aligned orientation atdistances of up to 200 mm between the coils. Some improvement wasobserved in the performance When the coils were arranged in a parallelorientation, in which the Rx coil continued to receive transmitted poweruntil a distance of about 300 mm. Examples of a wireless energy transfersystem according to the present disclosure were compared with efficiencyachievable by a system configured in accordance with the Qi 1.0standard. The size of the Tx coil in one simulated system was 52 mm×52mm×5.6 mm and a size of one Rx coil simulated was 48.2 mm×32.2 mm×1.1mm, and load impedance was 1 KOhm. Simulations were performed in analigned configuration with several Rx coil sizes, and example results ofsimulations performed are shown in FIG. 23.

Referring now also to FIGS. 4, 5A and 5B, a base unit 300 incorporatedin a mobile phone case form factor will be described, The base unit 300may include some or all of the components of base unit 100 describedabove with reference to FIG. 1. For example, the base unit 300 mayinclude a transmitting coil 312 (also referred to as Tx coil). Thetransmitting coil 312 is coupled to an electronics package 305, whichincludes circuitry configured to perform the functions of a base unit inaccordance with the present disclosure, including selectively and/oradjustably providing wireless power to one or more electronic devices.In some examples, the electronic device may be an electronic devicewhich is separated from the base unit (not shown in FIGS. 5A-5B). Insome examples, the electronic device may be the mobile phone 20, towhich the base unit 300 in the form of a case is attached.

The base unit 300 may provide a mobile wireless hotspot (e.g., chargingsphere 106) for wirelessly charging electronic devices that are placedor come into proximity of the base unit (e.g., within the chargingsphere). As will be appreciated, the base unit 300 when implemented inthe form of a mobile phone case may be attached to a mobile phone andcarried by the user, thus making the hotspot of wireless power mobileand available to electronic devices wherever the user goes. In examples,the base unit may be integrated with the mobile phone. The hotspot ofwireless power by virtue of being connected to the user's mobile phone,which the user often or always carries with him or her, thusadvantageously travels with the user. As will be further appreciated,opportunities for recharging the power cell on an electronic device wornby the user are frequent during the normal use of the mobile phone,which by virtue of being use may frequently be brought into the vicinityof wearable devices (e.g., eyewear devices when the user is making phonecalls, wrist worn devices when the user is browsing or using otherfunction of the mobile phone).

The Tx coil 312 and electronics (e.g., electronics package 305) may beenclosed in a housing 315. The housing 315 may have a portable formfactor. In this example, the housing is implemented in the form of anattachment member configured to be attached to a communication device inthis case a mobile phone (e.g., a mobile phone, a cellular phone, asmart phone, a two-way radio, and the like). In some examples, thecommunication device may be a tablet. In the context of this disclosure,a mobile phone is meant to include communication devices such as two wayradios and walkie-talkies. For example, the housing 315 may beimplemented in the form of a tablet case or cover (e.g., as illustratedin FIGS. 10A-C) or a mobile phone case or cover, e.g., as in the presentexample. In such examples, the base unit incorporated in the housing maypower an electronic device other than the communication device. Thehousing 315 may include features for mechanically engaging thecommunication device (e.g., mobile phone 20). In further examples, thehousing of the base unit may be implemented as an attachment memberadapted to be attached to an accessory, such as a handbag, a belt, orothers. Other form factors may be used, for example as described belowwith reference to FIG. 17.

In the examples in FIGS. 4 and 5A-5B, the base unit 300 includes atransmitting coil 312. The transmitting coil 312 includes a magneticcore 317 with conductive windings 316. The core 317 may be made of aferromagnetic material (e.g., ferrite), a magnetic metal, or alloys orcombinations thereof, collectively referred to herein as magneticmaterial. For example, a magnetic material such as ferrite and variousalloys of iron and nickel may be used. The coil 312 includes conductivewindings 316 provided around the core 317. It will be understood in thecontext of this disclosure that the windings 316 may be, but need notbe, provided directly on the core 317. In other words, the windings 316may be spaced from the core material which may be placed within a spacedefined by the windings 316, as will be described with reference toFIGS. 15-16. In some examples, improved performance may be achieved bythe windings being wound directly onto the core as in the presentexample.

The core 317 may be shaped as an elongate member and may have virtuallyany cross section, e.g., rectangular or circular cross section. Anelongate core may interchangeably be referred to as a rod 314, e.g., acylindrical or rectangular rod. The term rod may be used to refer to anelongate core in accordance with the present application, regardless ofthe particular cross sectional shape of the core. The core may include asingle rod or any number of discrete rods (e.g., 2, 3, 4, 5, 6, 7, 8, 9,10 or any other number greater than 10) arranged in patterns as will bedescribed. In the examples in FIGS. 4, 5A and 5B, without limitation,the transmitting coil comprises a single cylindrical rod positioned atleast partially along a first side (e.g., top side 321) of the housing315. In other examples, one or more coils may alternatively oradditionally be positioned along other sides, e.g., a bottom side 323,the left side 325 and/or right sides 327 of the housing 315.

The electronics package 305 (interchangeably referred to as electronicsor circuitry) may be embedded in the housing 315 or provided behind acover 307. In some examples, the cover 307 may be removable. In someexamples, it may be advantageous to replace the battery 320. In suchexamples, the battery 320 may be a separable component from theremaining circuitry. The battery 320 may be accessed by removing thecover 307. In some examples, the electronics package 305 may include abattery for storing energy from an external power source. In someexamples, the base unit 300 may alternatively or additionally receivepower from the mobile phone when powering the distance separatedelectronic device. In some examples, the base unit may not require abattery, and even smaller form factors may thus be achieved.

The base unit may be provided with one or more I/O devices 380. I/Odevices may be used to receive and/or transmit power and/or data via awired connection between the base unit and another device. For example,the base unit may include an I/O device 380 in the form of a USBconnector. The I/O device 380 (e.g., USB connector) may include a firstconnection side 382 (e.g., a female port) for coupling the base unit toexternal devices (e.g., a power source such as the power grid and/oranother electronic device). The I/O device 380 may include a secondconnection side 384 (e.g., a male connector) for coupling the base unitto the mobile phone, e.g., via a USB port of the mobile phone. One ormore of the signal lines 385 of the I/O device may be coupled to power,ground, and/or data lines in the base unit circuitry. For example, if aUSB connector with 5 lines is used, 2 lines may be used for data, 2lines may be used for power, and 1 line may be coupled to ground or usedfor redundancy. The signal lines 385 of the first and second connectionsides may be coupled to the base unit circuitry via a connector circuit386 (e.g., USB chip). It will be understood that any other type ofconnectors may be used, for example, and without limitation, an APPLELIGHTNING connector.

The base unit 300 may include a controller 330. The controller mayinclude functionality for controlling operations of the base unit, forexample controlling detection of electronic devices within proximity,selective transmission of wireless power upon detection of an electronicdevice, determination of status of the base unit, and selection oftransmission mode depending on the status of the base unit. Thesefunctions may be implemented in computer readable media or hardwiredinto an ASICs or other processing hardware. The controller mayinterchangeably be referred to as base unit processor.

The base unit may include one or more memory devices 360. The base unitmay include volatile memory 362 (e.g., RAM) and non-volatile memory 364(e.g., EEPROM, flash or other persistent electronic storage). The baseunit may be configured to receive data (e.g. user data, configurationdata) through wired or wireless connection with external electronicdevices and may store the data on board the base unit (e.g., in one ormore of the memory devices 360). The base unit may be configured totransmit data stored onboard the base unit to external electronicdevices as may be desired. In addition to user data, the memory devicesmay store executable instructions which, when executed by a processor(e.g., processor 360), cause the base unit to perform functionsdescribed herein.

The base unit 300 may include a charger circuit 332, which may beconfigured to protect the battery 320 from overcharging. The chargercircuit may be a separate chip or may be integrated within thecontroller 330. The base unit may include a separatetransmitter/receiver circuitry 340 in addition to the Tx coil 312 usedfor wireless power transmission. The transmitter/receiver circuitry 340may include a receiving/transmitting coil 342, e.g., an RF coil. Thetransmitter/receiver circuitry 340 may further include driver circuitry344 for transmission (e.g., RF driver circuit) and sense circuitry 346for reception of signals (e.g., RF sensing circuit). The base unit 300may include additional circuitry for wireless communication (e.g.,communication circuit 388). The communication circuit 388 may includecircuitry configured for Bluetooth, WiFi, GSM, or other communication.In some examples, the base unit 300 may include one or more sensor 370and/or one or more energy generators 350 as described herein. Additionalcircuitry providing additional functionality may be included. Forexample, the base unit 300 may include an image processor for processingand/or enhancement of images received from a wearable camera (e.g.,eyewear camera). The image processing functionality may be provided in aseparate IC (e.g., a DaVinci chip set) or it may be incorporated in aprocessor which implements the functions of controller 330.

In some examples, the housing may be configured to be mechanicallycoupled to a communication device, such as a mobile phone. In theexamples in FIGS. 4 and 5A-5B, the housing 315 is configured to providethe functionality of a mobile phone case. The housing may have a shapecorresponding to a shape of a communication device (e.g., a mobilephone). For example, the housing may be generally rectangular in shapeand may be sized to receive, at least partially, or enclose, at leastpartially, the communication device. In some examples, the housing maybe configured to cover only one side of the communication device. Insome examples, the housing may cover at least partially two or moresides of the communication device. In the examples in FIGS. 4 and 5A-5B,the housing 315 is configured to provide the functionality of a mobilephone case. The housing includes engagement features for coupling thebase unit to the communication device (e.g., mobile phone). For example,a receptacle 309 may be formed in the housing for receiving the mobilephone at least partially therein. The receptacle may be on a front sideof the housing. The base unit electronics may be provided proximate anopposite side of the receptacle. The coils may be placed around theperimeter of the housing, e.g. along any of the top, bottom, or left andright sides.

In some examples, systems described herein may maintain a surfacetemperature of components of the system to be at or below a particularlevel, e.g. less than 10 C above the ambient temperature for 30 minutesof continuous operation. In some examples, the surface temperature maybe maintained at a level less than 5 C over the ambient temperature.Temperature maintenance may minimize or reduce an acceleration of therate of discharge of batteries of the base unit, communication system g.mobile phone), and/or wearable electronic device.

Accordingly, example base units (which may be, for example, attached toa mobile phone) may include thermal management systems to remove heatfrom a surface of the base unit, such as a surface of the base unitadjoining a mobile phone or other device placed on or into the baseunit. Example thermal management systems may be passive, active, or acombination thereof. Active systems include (by way of example only)Peltier coolers and active flow devices such as miniature fans andelectrostatic tubules. Passive systems include (by way of example only)thermally-reflective material on the appropriate surfaces, passiveconvection channels, heat spreaders, and similar devices, vents. Ventscan be placed on any surface, but in some examples on a back surface tohelp reduce any temperature rise.

In some examples it may be advantageous to reduce or eliminateinterference with the operation of electronic devices caused by thetransmission of wireless energy. For example, such minimization may beadvantageous in systems utilizing mobile phones or other devices thatoperate over wireless communication frequencies.

Transmit frequencies may be selected, for example, which are spacedapart from common communication bandwidths. In some examples, shieldingtechniques may be used that may block or reduce the transmission ofcertain undesired frequencies while allowing desired frequencies to passthrough.

For example, power transfer may occur at one or more frequencies thatmay be several orders of magnitude below normal near field wirelesscommunication frequency bands and at power levels such that severaloctaves of the power transmit frequency or frequencies would be too weakto interfere with communication band signals.

In some examples shielding may be applied. The shielding can beimplemented using metals or other conductive materials to shieldtransmitted energy away from the direction of the transmitter andreceiver antenna of a communication system (e.g. smart phone) mounted onor positioned near the base unit. In some cases frequency selectivesurfaces may be used to implement the base unit and/or mobilecommunication device which only pass the power transmit frequency orfrequencies while blocking any multiple order of the transmit frequencythat might interfere with common communication band frequencies.Shielding may be implemented using active circuitry which may absorb andretransmit energy in a desired direction. This active circuitry may beimplemented as a conformal skin which includes embedded active andpassive components. The conformal skin may be used to implement the basestation and/or encase all or a portion of the base station. Theconformal skin may be used to implement an electronic wearable deviceand/or encase all or a portion of the electronic wearable device. Suchan approach may be used in some examples to increase efficiency ofenergy transfer to an intended wearable device by reducing energyabsorbed by other components.

In some examples, the power transmission components of the base unit maybe positioned such that they are removed physically from communicationelements used for normal smart or cell phone operation the powertransmission components may be placed in a base unit that is shaped toreceive a smart phone in a such a way that the smart phone'scommunication components are physically distant from the powertransmission components).

In sonic examples, unidirectional antenna design may be provided toreduce or eliminate interference from transmitted power energy with thetraditional communication signals coming to and from a mobile phone.

In some examples, such as where a mobile phone has built in wirelesscharging for the mobile phone's battery, the base unit, if a separateunit from the mobile phone, may have its transmit coils located is sucha manner as to allow clear transmission of the charging energy from thebase unit to reach the charge coils of the phone charging system. Insome examples the base unit may charge both the smart phone and the baseunit batteries with the same wireless charging system. In general,design of base units to accept a particular mobile phone may providecustom designs for mechanical interfacing, an/or may be designed to workwith and in conjunction with other electronic components in the mobilephone. This may include, by way of example only, charging systemsconnected wirelessly, or directly through connections such standard USBconnections including USB type C.

In some examples, the base unit may be implemented in a subsystem of amobile phone. In these embodiments, the base unit can be designed so asto not interfere with other subsystems of the mobile phone.

The base unit can transmit to an electronic wearable device over adistance of 6 inches or more 10 watts or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 6 inches or more 5 watts or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 6 inches or more 2 watts or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 6 inches or more a 1 watt or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 6 inches or more 1 milliwatt or less of transmittedwireless power. The base unit can transmit to an electronic wearabledevice over a distance of 6 inches or more 100 microwatts or less oftransmitted wireless power. The electronic wearable device can transmitdata to a base unit over a distance of 6 inches or more when using 1watt or less of transmitted wireless power. The electronic wearabledevice can transmit data to a base unit over a distance of 6 inches ormore when using 1 milliwatts or less of transmitted wireless power. Theelectronic wearable device can transmit data to a base unit over adistance of 6 inches or more when using 100 microwatts or less oftransmitted wireless power. The electronic wearable device can transmitdata to a base unit over a distance of 6 inches or more when using 10nanowatts or more of transmitted wireless power. The electronic wearabledevice can transmit data to a base unit over a distance of 6 inches ormore when using 10 nanowatts or less of transmitted wireless power.

The base unit can transmit to an electronic wearable device over adistance of 1 inch or more 10 watts or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 1 inch or more 5 watts or less of transmitted wirelesspower. The base unit can transmit to an electronic wearable device overa distance of 1 inch or more 2 watts or less of transmitted wirelesspower. The base unit can communicate to an electronic wearable deviceover a distance of 1 inch or more a 1 watt or less of transmittedwireless power. The base unit can transmit to an electronic wearabledevice over a distance of 1 inch or more 1 milliwatt or less oftransmitted wireless power. The base unit can transmit to an electronicwearable device over a distance of 1 inch or more 100 microwatts or lessof transmitted wireless power. The electronic wearable device cantransmit data to a base unit over a distance of 1 inch or more whenusing 1 watt or less of transmitted wireless power. The electronicwearable device can transmit data to a base unit over a distance of 1inch or more when using 1 milliwatts or less of transmitted wirelesspower. The electronic wearable device can transmit data. to a base unitover a distance of 1 inch or more when using 100 microwatts or less oftransmitted wireless power. The electronic wearable device can transmitdata to a base unit over a distance of 1 inch or more when using 10nanowatts or more of transmitted wireless power. The electronic wearabledevice can transmit data to a base unit over a distance of 1 inch ormore when using 10 nanowatts or less of transmitted wireless power.

With reference now also to FIGS. 6-8, operations of a base unit inaccordance with some examples herein will be described. FIG. 6illustrates a process 400 for wirelessly charging an electronic device200 which is separate from (e.g., not attached to) the base unit (e.g.,base unit 100 or 300). As described, the base unit may be implemented asan attachment member configured for coupling to a communication device,such as a mobile phone 20. The base unit may be integrated into thecommunication device in other examples. The base unit (e.g., base unit100 or 300) may be used to charge another device other than the mobilephone 20 to which it is attached, although the present disclosure is notthus limited and charging the mobile phone 20 with the base unit is alsoenvisioned. Generally, the base unit may be movable with relation to theelectronic device 200, which may remain attached to the user (e.g.,attached to a body part of the user directly or via a wearableaccessory) while the electronic device is in use (e.g., while a hearingaid is used to enhance a user's hearing).

In the illustrated example, the mobile phone 20 may be moved to aposition in which the mobile phone 20 and base unit (e.g., base unit 100or 300) attached thereto or incorporated therein are proximate to theelectronic device 200 (e.g., eyewear camera 205 in FIG. 8), as shown inblock 420, In the illustrated the electronic device is a camera howeverit will be understood that this exemplary process is applicable to otherelectronic devices, such as a hearing aid. For example, the user 5 maybring the mobile phone 20 near the user's head in order to conduct acall. During this time, the electronic device may in proximity to thebase unit (e.g., within the charging range of the base unit) and maywirelessly receive power from the base unit to either power or chargethe electronic device.

The base unit (e.g., base unit 100 or 300) may be configured toselectively transmit power. For example, the base unit array beconfigured to preserve energy during times when electronic devices arenot sufficiently close to the base unit to receive the power signals.The base unit may be configured to stop transmission of power when nocompatible electronic devices are detected in proximity.

Prior to initiating power transmission, the base unit (e.g., base unit100 or 300) may detect an electronic device in proximity, e.g., as shownin block 430. The electronic device may be in proximity for chargingwhile remaining separated by a distance from the base unit. That is, theelectronic device may be in proximity for charging even though theelectronic device does not contact the base unit. In some examples, theelectronic device may broadcast a signal (block 410), which may bedetected by the base unit. The signal may be a proximity signalindicating the presence of the electronic device. The signal may becharge status signal, which provides also an indication of the chargelevel of the power cell within the electronic device. When theelectronic device is within a communication range of the base unit, thebase unit may detect the signal broadcast by the electronic device andmay initiate power transfer in response to said signal. Thecommunication range may be substantially the same as the charging range.In some examples, the communication range may be smaller than thecharging range of the base unit to ensure that electronic devices areonly detected when well within the charging range of the base unit. Theelectronic device may remain in proximity as long as a distance betweenthe base unit and the electronic device remains equal to or less thanthe threshold distance (e.g., charging range).

In some examples, broadcasting a signal from the electronic device maybe impractical, e.g., if limited power is available onboard theelectronic device. The base unit may instead transmit an interrogationsignal. The interrogation signal may be transmitted continuously orperiodically. The electronic device may be configured to send a signal(e.g., proximity signal, charge status signal, charging parameters suchas but not limited to, charging frequency, power requirement, and/orcoil orientation) responsive to the interrogation signal. In someexamples, redundant detection functionality may be included such thatboth the base unit and the electronic device broadcast signals and thedetection is performed according to either of the processes describedwith reference to blocks 405 and 410.

The base unit (e.g., base unit 100 or 300) may wirelessly transmit powerto the electronic device 200 (block 440) while one or more conditionsremain true. For example, the base unit may continue to transmit powerto the electronic device while the electronic device remains within thecharging zone of the base unit or until the power cell of the electronicdevice is fully charged. With regards to the latter, the electronicdevice may transmit a charge status signal when the power cell is fullycharged and the base unit may terminate broadcast of power signals whenthe fully charged status signal is detected. In some examples,alternatively or in addition to sending a fully charged status signal,the electronic device may include a charging circuit which is configuredto protect the power cell of the electronic device by turning offcharging once the power cell is fully charged. In this manner, anindividual electronic device may stop receiving power while the baseunit continues to transmit, e.g., in the event that multiple devices arebeing charged.

In some examples, the base unit may be configured to periodically orcontinuously send interrogation signals while broadcasting powersignals. The interrogation signals may trigger response signals fromelectronic devices 200 in proximity. The response signals may beindicative of whether any electronic devices remain in proximity and/orwhether any devices in proximity require power. The base unit may beconfigured to broadcast power until no electronic devices are detectedin proximity or until all charge status signal of electronic device inproximity are indicative of fully charged status.

In some examples, the base unit (e.g., base unit 100 or 300) may befurther configured to adjust a mode of power transmission. The base unitmay be configured to transmit power in a low power mode, a high powermode, or combinations thereof. The low power mode may correspond to apower transfer mode in which power is broadcast at a first power level.The high power mode may correspond to a power transfer mode in whichpower is broadcast at a second power level higher than the first powerlevel. The low power mode may correspond with a mode in which power isbroadcast at a body-safe level. The base unit may be configured todetect a state of the base unit, as in block 450. For example, a sensor(e.g., an accelerometer, a gyro, or the like) onboard the base unit maydetect a change in the position or orientation of the base unit, or achange in acceleration, which may indicate that the base unit is beingheld or moved towards the user's body. The controller may be configuredto determine if the base unit is stationary (block 460) and change thepower mode responsive to this determination. For example, if the baseunit is determined to be stationary, the base unit may transmit power inhigh power mode as in block 470. If the base unit is determined not tobe stationary, the base unit may reduce the power level of power signalstransmitted by the base unit. The base unit may change the mode of powertransmission to low power mode, as shown in block 480. The base unit maycontinue to monitor changes in the state of the base unit and may adjustthe power levels accordingly, e.g., increasing power level again to highonce the base unit is again determined to be stationary. The sensor maymonitor the state of the base unit such that power transmission isoptimized when possible while ensuring that power is transmitted at safelevels when appropriate (e.g., when the base unit is moving for exampleas a result of being carried or brought into proximity to the user'sbody).

In some examples, the base unit may be communicatively coupled to thecommunication device (e.g. mobile phone 20). The mobile phone 20 may beconfigured to execute a software application which may provide a userinterface for controlling one or more functions of the base unit. Forexample, the software application may enable a user 5 to configure powerbroadcast or interrogation signal broadcast schedules and/or monitor thecharge status of the base unit and/or electronic device coupled thereto.The software application may also enable processing of data received bythe base unit from the electronic device(s). FIG. 7 illustrates a flowchart of a process 500 for wireless power transfer in accordance withfurther examples herein. In the example in FIG. 7, the base unit iscommunicatively coupled to the mobile phone such that the mobile phonemay transmit a command signal to the base unit. The command signal maybe a command to initiate broadcast of interrogation signals, as shown inblock 505. The base unit may transmit an interrogation signal (block510) responsive to the command signal. Proximity and/or charge statussignals may be received from one or more electronic devices in proximity(block 515). Upon detection of an electronic device in proximity, thecontroller of the base unit may automatically control the transmitter tobroadcast power signals (block 520). In some examples, an indication ofa detected electronic device may be displayed on the mobile phonedisplay. The mobile phone may transmit a command signal under thedirection of a user, which may be a command to initiate power transfer.The base unit may continue to monitor the charge status of theelectronic device (e.g., via broadcast of interrogation signals andreceipt of responsive charge status signals from the electronic device),as shown in block 525. Broadcast of power from the base unit may beterminated upon the occurrence of an event, as shown in block 530. Theevent may correspond to receiving an indication of fully charged statusfrom the one or more electronic devices being charged, receiving anindication of depleted stored power in the battery of the base unit, ora determination that no electronic device remain in proximity to thebase unit. In sonic example, the broadcast of power may continue but ata reduced power level upon a determination that the base unit is inmotion (e.g., being carried or moved by a user 5).

Examples described herein may provide a low cost, small form factor,light weight portable base unit (e.g. wireless power charging unit) thatcan receive its power from other electronic devices. Upon or afterreceiving power from an external source the base unit can be used forpowering electronic devices with wireless power to either Charge abattery or capacitor of an electronic device or to power the electronicdevice directly. The electronic device can be, by way of example only, awatch, band, necklace, earring, ring, head wear, hearing aid, hearingaid case, hearing aid control unit, eyewear, augment reality unit,virtual reality unit, implant, clothing article, wearable article,implanted device, cell phone. Base units described herein may include atransmitter, external power port and associated electronics. Thetransmitter can be comprised of a metal winding, by way of example onlycopper wire, around a magnetic material core. The transmitter core cancomprise one of, by way of example only, iron, ferrites, iron alloys, amu metal, Vitroperm 500F, a high permeability metal. The transmitter cancomprise a ferrite core. The winding can be of a copper wire. Thewinding can be of Litz wire. The external power port can be a USB port.The USB port can be electrically connected to one of a; lap top, desktop, cell phone, smart pad, communication system, Mophie Case,rechargeable cell phone case, or other source of power, In this manner,the base unit may be formed as a “dongle” or other accessory devicehaving a USB or other electronic interface to a power source and awireless transmitter. The transmitter can be wireless coupled to adistance separated receiver of an electronic device. The electronicdevice can be an electronic wearable device. The portable charging unitcan be devoid of a battery. The portable charging unit can be devoid ofa power source. Example base units may include at least one USBconnector, an RF source for generation a time varying signal, saidsignal being provided to an RF antenna or a magnetic coil. Example baseunits may include a ferrite core and copper wire windings.

Example base units may accordingly be powered by a 3rd party powersource. Such a 3^(rd) party power source can be, by way of example only,that of a computer, laptop, cell phone, smart pad, an electrical powersocket, or combinations thereof.

Some example base units may include a battery, which in sonic examplesmay be a very small form factor battery, or capacitor should one bedesirable for minimal power source to keep electronics functional ifpower from the source were to fluctuate or otherwise be momentarilyunavailable.

Example base units may be incorporated in and/or used with a smart phonecase and used to power a smart phone battery or provide battery back upto a smart phone. The said smart phone case may include a recess foraccepting a smart phone, and a standard USB connector that may be usedto charge the battery in the smartphone case and/or the battery in thesmart phone place in said case. The smart phone case may include a USBpower output port that may be used to power any external device from thebattery in the smart phone case, including but not limited to the baseunit. A smart phone may have a normal USB port that provides the normalcharging and data function of a typical smart phone. The said smartphone may also include a USB port that provides power to other externaldevices including but not limited to, a portable wireless charging unit(e.g. base unit) which may be coupled to the USB port.

As previously described, example base units may include a plurality ofcoils and/or a plurality of rods arranged in a pattern. FIGS. 9A-9Eillustrate a base unit which includes two coils. The base unit mayinclude some or all of the features of the base units in FIGS. 1-8, thustheir description will not be repeated. For example, the base unit 700may include at least one Tx coil 712 and circuitry 705 configured toprovide the functionality of a base unit in accordance with the presentdisclosure. The coils and circuitry 705 may be enclosed or embedded in ahousing 715. The base unit 700 includes a first coil 712-1 and a secondcoil 712-2. In some examples, both the first and the second coils may beconfigured for wireless power transmission. In some examples, the firstcoil 712-1 may be configured as a transmitting coil and the second coil712-2 may be configured as a receiving coil. The first and second coilsmay extend, at least partially, along opposite sides of the housing 715.For example, the first coil 712-1 may be provided along the top side andthe second coil 712-2 may be provided along the bottom side of thehousing 715. Terms of orientation, such as top, bottom, left and right,are provided for illustration only and without limitation. For example,the terms top and bottom may indicate orientation of the base unit whencoupled to a mobile phone and during typical use, e.g., a top side ofthe base unit may be closest to the top side of the mobile phone, thebottom side of the base unit closest to the bottom side of the mobilephone, and so on. In some examples, the base unit may alternatively oradditionally include coils that are arranged along any side or face ofthe housing, including the left and right sides, or near the front orback faces of the housing. In some examples, the Tx coils or componentsthereof may be located in a central portion of the base unit, as will bedescribed further below. The housing includes a receptacle 709 forcoupling a communication device (e.g., mobile phone) thereto. Thereceptacle 709 may include engagement features for mechanicallyconnecting a communication device to the mobile phone. For example, thehousing may be made from a rigid plastic material and the receptacle maybe configured such that the communication device snaps into engagementwith the mobile phone. In some examples, the housing may be made, atleast partially, for a resilient plastic material (e.g., rubber) and atleast a portion of the housing may be deformed (e.g., elongated orflexed) when placing the mobile phone in the receptacle 709. Additionalexamples of base unit housings and engagement features are describedwith reference to FIGS. 10-12 below.

FIGS. 10A-10C illustrate a base unit 800 having a housing 815 in theform of a case for a communication device 30. The communication device30 may be a tablet or smart phone. The housing 815 may enclose thecircuitry 801 of the base unit. The housing 815 may include a receptacle809 which is configured to receive the communication device 30 (e.g.,tablet or smart phone). In this example, the receptacle 809 isconfigured for sliding engagement with the communication device 30,e.g., tablet, by sliding the communication device into the receptacle809 from a side (e.g., a top side) of the housing. In other examples,the receptacle 809 may be configured for snap engagement with thecommunication device 30 (e.g., tablet or smart phone). In furtherexamples, the housing 815 may be configured to be resiliently deformed,at least partially, when being attached to the communication device 30.The communication device 30 may be seated in the receptacle 809 with atleast a portion of the housing 815 projecting from the base unit 800. Insome examples, the communication device 30 may be, at least partially,enclosed by the housing 815 such that the display face 31 of thecommunication device 30 (e.g., tablet or smart phone) is substantiallyflush with the front surface 817 of the housing.

FIGS. 11A-11D illustrate a base unit 900 having a housing 915 in theform of a partial case for a communication device 15. The communicationdevice 15 may be a mobile phone, a tablet, or the like. The partial casemay attach to and/or enclose a portion (e.g., a bottom portion, a topportion) of the communication device 15. The housing 915 may enclose thecircuitry 901 of the base unit 900. The base unit 900 may include areceptacle 909 formed in the housing 915. The receptacle 909 may beconfigured for snap engagement with the communication device 15. By snapengagement, it may be generally implied that one or more engagementfeatures of the receptacle are shaped/sized for an interference fit withat least a portion of the communication device and the one or moreengagement features are temporarily deformed to receive thecommunication device in the receptacle. In other examples, thereceptacle 909 may be configured for slidable engagement with thecommunication device 15 in a manner similar to the example in FIG. 10.

FIGS. 12A and 12B illustrate a base unit 1000 having a housing 1015according to further examples herein. The housing 1015 may be similar tohousing 915 in that it may be a partial case configured to attach toonly a portion of the communication device 15. The housing 1015 mayenclose the circuitry 1001 of the base unit 1000. A movable cover 1019may be attached to the housing 1015. The movable cover 1019 may behinged at one or more locations to allow the cover 1019 to be moved outof the way to access the communication device 15. In some examples, anattachment member may be coupled to the housing 1015, cover 1019 orboth. The attachment member 1003 may be configured to allow the user toconveniently carry the base unit 1000 and communication device 15attached thereto. For example, the attachment member 1003 may be a clip,a loop or the like, for attaching the base unit to clothing/accessories.The movable cover may be secured in a closed position via a conventionalfastener (e.g., a snap, a magnetic closure, or others).

FIGS. 13 and 14A-14C illustrate a base unit according to furtherexamples of the present disclosure. The base unit 1100 may include someor all of the features of base units described herein and similaraspects will thus not be repeated. For example, the base unit 1100 mayinclude a wireless power transmitter (e.g., Tx coil 1112), a battery(1120) and base unit circuitry (1105). The battery 1120 and circuitry1105 may be provided in a central portion of the base unit 1100, whilethe Tx coils 1112 may be provided along peripheral portions of the baseunit 1100. The battery 1120 may be rechargeable and/or removable, Ahousing 1115 of the base unit may be configured as an attachment member,e.g., for attaching the base unit to a communication device, for examplea mobile phone 20. The housing may have perimeter sides (e.g., a topside, bottom side, left and right sides, which are arbitrarily describedas top, bottom, left and right to illustrate the relative orientation ofthe base unit to a mobile phone when coupled thereto). In the examplesin FIGS. 13 and 14A-14C, the Tx coils are arranged parallel to theperimeter sides (e.g. along peripheral portions) of the base unit.

The transmitter may include a single continuous Tx coil or a segmentedTx coil. In the example in FIG. 13, the transmitter includes a segmentedcoil including a plurality of discrete Tx coils (in this example fourcoils 1112-1, 1112-2, 1112-3, and 1112-4), each having a magnetic corewith conductive windings wound thereon. A diameter o of the Tx coils mayrange from about 5 mm to about 20 mm. In some examples, the diameter oof the Tx coils may be between 8 mm to 15 mm. In some examples, thediameter o of the Tx coils may be 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, or14 mm. Different diameters for the coils may be used. The magnetic coresin this example are implemented as elongate cylindrical rods made from amagnetic material. The rods in this example are arranged around theperimeter of the base unit 1100. In some examples, the rods may extendsubstantially along the full length of the top side, bottom side, leftand right sides of the housing 1115. Lengths (1), widths (w), andthicknesses (t) of the housing 1115 may range from about 150 mm-180 mm,80-95 mm, and 15-25 mm, respectively. Other lengths, widths, andthicknesses may be used, e.g., to accommodate a given communicationdevice (e.g. smartphone) and/or accommodate a particular coil size. Forexample, a housing configured to couple to an iPhone 6 mobile phone maybe about 160 mm long, about 84 mm wide, and about 19 mm thick andaccommodate Tx coils having a diameter of about 9 mm. In anotherexample, the housing may have a length of about 165 mm, a width of about94 mm, and a thickness of about 21 mm accommodating a coil having adiameter of about 14 mm.

In certain embodiments, the transmit coils maybe driven in a phased ortime sequenced manner so as to maximize the transmitted power that canbe applied to each coil individually at any given time, creating arotating magnetic field with the largest possible charging range fromthe base unit. Such approaches provide enhanced orientation and rangeindependence of the charging system.

The base unit includes a receptacle 1109, 1209 for receiving the mobilephone 20. In this example, the receptacle is configured to receive themobile phone such that the mobile phone is substantially flush with afront face of the housing. The receptacle 1109, 1209 may have a size andshape substantially matching the size and shape of the mobile phone suchthat the mobile phone is substantially enclosed on five sides by thehousing. In some examples, the receptacle may have a size and/or shapeselected to partially enclose the mobile phone. The mobile phone mayproject from the housing when engaged thereto (e.g., as illustrated inthe examples in FIGS. 10 and 11), which may further reduce the formfactor of the base unit.

In some examples, the windings may be spaced from the surface of therod(s), e.g., as in the examples in FIGS. 15A-15C and 16A-16C describedfurther below.

In some examples, it may be desirable to maximize the number of windingsor length of wire used in the windings. A base unit having a generallyflattened parallelepiped shape may have four perimeter sides (top,bottom, left and right sides) and two major sides (front and backsides). The number of windings or length of wire used in the windingsmay maximized by placing the windings at the peripheral portion of thedevice. For example, the conductive wire may be wound with the loopssubstantially traversing the perimeter of the base unit (e.g., asdefined by the top, bottom, left and right sides). FIGS. 15A-15Cillustrate examples of base units 1300 a-c in which conductive windings1316 are provided at the perimeter of the base unit and the corematerial (e.g., core rods 1314) is provided in an interior portion ofthe base unit spaced from the windings. Base unit 1300 a includesindividual rods 1314 which are arranged with their centerlinesperpendicular to a major side (e.g., front or back side) of the baseunit. Base units 1300 b and 1300 c include individual rods 1314 whichare arranged with their centerlines arranged parallel to a perimeterside of the base unit.

In further examples, the conductive wire may be wound such that the wireis in a plane substantially parallel to a major side of the base unit.For example, base unit 1400 a includes a core material in the form of acore plate 1417 and windings wrapped around the core plate with the coilaxis substantially parallel to the left and right sides of the baseunit. Base units 1400 b and 1400 c includes windings 1416 similar to thewindings of base unit 1400 a but using discrete rods 1414 as corematerial, the rods spaced inwardly from the windings and arrangedparallel to a perimeter side of the base unit. Non-magnetic material maybe provided in the spaces between the rods in the examples in FIGS.15A-15C and 16A-16C Different combination of orientations of thewindings and rods than the specific examples illustrated may be used inother examples.

The base unit may be incorporated in a variety of shapes which may havea relatively small form factor. The base unit may be incorporated into aform factor which is portable, e.g., fits in a user's hand and/or easyto carry in the user's pocket, handbag, or may be attachable to awearable accessory of the user). For example, referring now also to FIG.17 base unit 1500 may have a housing 1515 which has a generallycylindrical shape (e.g., puck shape). A puck base unit 1500 may includesome or all of the components of base units described herein and thedescription of such components will not be repeated. For example, thebase unit may include a transmitter (e.g. Tx coil 1512), a. battery anda. controller (not shown). The housing 1515 may have a first major side(e.g., a base) and a second major side (e.g., a top). The Tx coil may beplaced along the perimeter (e.g., proximate and extending, at leastpartially, along the cylindrical perimeter side) of the base unit. Insome examples, the core may be in the shape of a cylindrical core plate.The coil windings, cylindrical core plate, and cylindrical puck may becoaxially aligned. The base unit 1500 may include one or more inputports 1560 for connecting the base unit to external power and/or anothercomputing device. For example, the base unit 1500 may include a firstinput port 1560-1 for coupling AC power thereto and a second input port1560-2 (e.g., USB port) for coupling the base unit to a computingdevice, e.g., a laptop or tablet. The base unit 1500 may include one ormore Charge status indicators 1590. The charge status indicators 1590may provide visual feedback regarding the status and/or charging cycleof the base unit, the electronic devices in proximity, or combinationsthereof.

A charge status indicator in the form of an illumination device 1592 maybe provided around the perimeter of the base unit or the perimeter of amajor side of the base unit. The illumination device may include aplurality of discrete light sources. Individual ones or groups ofindividual light sources may provide status indication for individualelectronic devices which may be inductively coupled to the base unit forcharging. In some examples, an indicator display 1594 may be provided ona major side e.g., a top side) of the base unit. The indicator displaymay be configured to provide individual charge status indications forone or more electronic devices inductively coupled to the base unit forcharging.

FIG. 18 illustrates components of a transmitter and receiver circuitsfor a wireless power transfer system in accordance with the presentdisclosure. On the transmitter side of the system, the transmitting coilis represented by an inductance L11. The transmitter circuit is tuned tobroadcast at desired frequency. To that end, the transmitter circuitincludes capacitor C1PAR and resistor R1PAR, which may be selected totune the transmitter to the desired transmit resonance frequency. On thereceiver side of the system, the receiving coil is represented by aninductance L22, and capacitor C2 and resistor R22 are chosen to tune theRLC circuit produced by the inductance of the receiving coil and C2 andR22 to the transmit resonance frequency produced by the transmittingcoil. A rectifier (e.g. a full wave rectifier) is made from four diodesD1, D2, D3, and D4. The rectifier in combination with the load circuitmade up for RLoad., Cload, and Lload and convert the alternating signalinduced in L22 to DC voltage output for charging the battery of thedevice. The load resistor RLoad and the load capacitor CLoad areselected to impedance match the diode bridge to the charging circuit forthe battery used in the wearable device.

In some embodiments the transmitting coil and thus the inductance L11 isrelatively large compared to the inductance of the receiving coil andits inductance L22. When the transmitting and receiving coils are inclose proximity the transfer efficiency is relatively high. At largerdistances the efficiency is reduced but remains relatively high comparedto other systems, such as a Qi standard compliant systems. This isillustrated in FIGS. 19-21.

In sonic examples, the shape of the pattern of a magnetic field betweeninductively coupled transmitting and receiving coils in accordance withthe present disclosure may be largely omnidirectional withwell-established nulls at the top and bottom of the coils. The radiationpattern can be directed by placing the coil against or near a reflectingground plane to produce more of a unidirectional pattern.

FIG. 22 illustrates an example of magnetic field lines emanating from atransmitting coil and the field at the receiving coil when the positionof the receiving coil is well known or predictable (e.g., in typical usescenarios). In such example, directed flux approach may be used toimprove the efficiency of energy transfer.

By careful specification of the use cases for the charging system of thewearable device, a. wireless power transfer system can be optimized toproduce an improved arrangement of charging conditions while preservingform factor through a reduction of battery size needed to normallycharge a device for its typical use period between charging cycles. Insome applications, the electronic device may not need to beintentionally placed in a manner to facilitate charging, since the powertransmitted at the use case distance may be adequate for maintaining theenergy draw from the system on the battery.

Examples described herein may make use of body-worn repeaters. The useof body-worn repeaters may, for example, improve system performanceand/or relax requirements on base units and/or wearable electronicdevices described herein.

Generally, body-worn repeaters described herein are configured toreceive wireless power from a base unit described herein and providewireless power to one or more wearable electronic devices. Bypositioning a body-worn repeater between a base unit and a wearableelectronic device (e.g. such that a distance between the body-wornrepeater and the wearable electronic device is less than a distancebetween the base unit and the wearable electronic device), range of theoverall system may be improved. For example, it may be disadvantageous,impractical, or impossible to provide power from the base unit over theentire distance between the base unit and the wearable electronicdevice. However, placement of a body-worn repeater may allow thewireless power to be relayed from the base unit to the wearableelectronic device.

Moreover, body-worn repeaters may improve efficiency of wireless powertransfer by reducing orientation dependencies between a base unit and awearable electronic device. For example, base units described herein mayinclude a magnetic core and may have increased efficiency with areceiving device when in a particular orientation, or range oforientations. By placing a body-worn repeater to mediate wireless powertransfer, one orientation is provided between the base unit and thebody-worn repeater, and another between the body-worn repeater and awearable electronic device. Accordingly, the orientation between thebase unit and the body-worn repeater may be Closer aligned than theorientation between the base unit and the electronic wearable device.The orientation between the body-worn repeater and the electronicwearable device may be closer aligned than the orientation between thebase unit and the electronic wearable device.

In some examples, body-worn repeaters described herein may reducecomplexity that may otherwise be required in base units. For example,one body-worn repeater may provide wireless power to a plurality ofwearable electronic devices, and certain of the wearable electronicdevices may have different carrier frequency and/or modulation (e.g. fordata transfer) parameters. Examples of body-worn repeaters describedherein may be tuned (e.g. using a controller or other processing unitforming part of the body-worn repeater) to have a different carrierfrequency and/or different frequency modulation based on the identitiesof wearable electronic devices with which the body-worn repeater iscommunicating. In this manner, a base unit may provide power to abody-worn repeater using one frequency and/or modulation scheme, and thebody-worn repeater may utilize multiple frequencies and/or modulationschemes to communicate with different wearable electronic devices. Insome examples, this may relieve the base unit of the need to itselfprovide different frequencies and/or modulation schemes.

FIG. 23 is a schematic illustration of a system in accordance withexamples described herein. The system 2300 includes base unit 2302,body-worn repeater 2304, and wearable electronic device 2306. Thebody-worn repeater 2304 is configured to receive wireless power frontthe base unit 2302 and provide wireless power to the wearable electronicdevice 2306. The base unit 2302 may be implemented using any examplebase units described and/or depicted here. Generally, the base unit 2302may include a transmitter for wireless power delivery, the transmittermay include a coil comprising a magnetic core. The base unit 2302 mayfurther include a battery coupled to the transmitter. The base unit 2302may further include a controller coupled to the battery and thetransmitter and configured to cause the transmitter to selectivelytransmit power from the battery. The base unit 2302 may further includea housing enclosing the transmitter, the battery, and the controller.

In some examples, the base unit 2302 may be implemented as a case thatmay be attached to a mobile communication system, e.g., a mobile phone,in some examples, the base unit 2302 may be implemented as somethingthat may be worn on a body, e.g. attached or integral to a belt. In someexamples, the base unit 2302 may be worn by the user in or on, forexample, a pocket, necklace, tether, shoe, belt, ankle band, wrist band,armband, or attached to, on, or part of one of a cell phone or mobilephone.

The body-worn repeater 2304 generally includes a coil configured toreceive wireless power from the base unit 2302. The coil may beimplemented using any coils described and/or depicted herein, includinga coil having a magnetic core. In some examples, the coil of thebody-worn repeater 2304 may be a flat (e.g. planar) coil without amagnetic core. Generally, the body-worn repeater 2304 may be implementedusing any base unit described and/or depicted herein. Some examples ofbody-worn repeaters may not, however, include a battery and/or memory.The body-worn repeater 2304 may further include one or more electroniccircuits having an inductance, capacitance, and resistance. Theelectronic circuit(s) may present an inductance, capacitance, and/orresistance selected to match and/or improve matching with the wearableelectronic device 2306 and/or the base unit 2302.

In some examples, the body-worn repeater 2304 may be implemented usingprimarily passive components. For example, the body-worn repeater 2304may be implemented using a resonator that may capture energy from thetransmitter (e.g. in the base unit 2302) and relay that energy to theelectronic wearable device (e.g. the wearable electronic device 2306)without any further modification or conditioning other than thatproduced by the resonant behavior of the body-worn repeater. Forexample, such a repeater may be implemented using a resonator made ofpassive components, including a wire-wound ferrite core, one or morecapacitive elements (e.g. capacitors), and/or one or more resistiveelements (e.g. resistors).

In some examples, the body-worn repeater 2304 may include at least twocoils—one or more coils selected to receive wireless power from the baseunit 2302 and one or more coils selected to transmit wireless power fromthe body-worn repeater 2304 to the wearable electronic device 2306. Insome examples, the coil size and type (e.g. with or without magneticcore, flat or wound around core) may be selected to facilitate receiptand/or transmission of power accordingly. One or more circuits may beprovided to present a resistance, capacitance, and/or inductanceassociated with each coil to match or improve a matching with a pairedtransmitter or receiver Base unit 2302 or wearable electronic device2306). One or more switches may be included to switch from receipt ofpower by one coil to transmission of the power by another coil. Examplerepeaters including multiple coils may be designed to have optimumtransfer of wireless power between the coils. In some examples, multiplecoils may be implemented having a common core. The body-wont repeatermay be designed to function as a resonator. The repeater functioning asa resonator may have a single coil that supports the same modulationfrequency as the base unit and the wearable electronic device.

The body-worn repeater 2304 may include (by way of example only) one ormore antennas, transmitters, coils, ASICs, circuitry including one ormore capacitors, A to D converters, one or more inductors, one or morememory units, which may be volatile or non-volatile, an energy storageunit such as (by example only) a rechargeable battery or a supercapacitor, charge pumps to amplify voltage, and/or one or more switches.

The body-worn repeater 2304 may include circuitry for tuning thebody-worn repeater 2304 to transmission at a particular frequency and/oruse of a particular modulation scheme based on an identity of thewearable electronic device 2306, or other wearable electronic deviceswith which the body-worn repeater 2304 will communicate.

The body-worn repeater 2304 may be attached to or integral with itemsthat are intended to be worn by a user. For example, the body-wornrepeater 2304 may be located in a ring, watch, bracelet, necklace,earring, hair band, hair clip, shoe, belt, broach, clip, or combinationsthereof. In some examples, the body-worn repeater 2304 may be located inor attached to a mobile communication system (e.g. cell phone).

In some examples, the body-worn repeater 2304 may house or attach to thewearable electronic device 2306. In some examples, the body-wornrepeater 2304 may include an attachment mechanism for physicalattachment to the wearable electronic device 2306. The body-wornrepeater 2304 may be mobile. For example, the body-worn repeater 2304may be worn by a user that may be mobile—for example by crawling,walking, driving, or flying.

The wearable electronic device 2306 generally includes a coil configuredto receive wireless power from the body-worn repeater 2304. The wearableelectronic device 2306 may be implemented using any wearable electronicdevices described and/or depicted herein. Any coil described and/ordepicted herein may be used to implement the wearable electronic device2306. A coil in the body-worn repeater 2304 may, during operation,excite and energize a coil in the wearable electronic device 2306.

In some examples, the wearable electronic device 2306 may be implementedto provide the functionality of an audio system, heads up display,hearing aid, directional microphone, camera, camera system, infraredvision system, night vision aid, light, one or more sensors, pedometer,wireless cell phone, mobile phone, wireless communication system,projector, laser, augmented reality system, virtual reality system,holographic device, radio, sensor, GPS, data storage, power source,speaker, fall detector, alertness monitor, geo-location, pulsedetection, gamming, eye tracking, pupil monitoring, alarm, CO2 detector,UV meter, poor air monitor, bad breath monitor, thermometer, smokedetector, pill reminder, alcohol monitor, switch, or combinationsthereof.

In some examples, the base unit 2302 and/or body-worn repeater 2304 canbe located within the room, vehicle or space near the wearer (e.g. thebody-worn repeater may not always be worn by the user).

Body-worn repeater 2304 may be positioned such that it is between thebase unit 2302 and the wearable electronic device 2306, for example suchthat a distance between the body-worn repeater 2304 and the wearableelectronic device 2306 is less than a distance between the base unit2302 and the wearable electronic device 2306. For example, in FIG. 23,the base unit 2302 is worn on a user's belt, while the body-wornrepeater 2304 is worn in or on a necklace, and the wearable electronicdevice 2306 is located on eyewear worn by the user.

In some examples, the body-worn repeater 2304 may be located within therange of 0.1 millimeters to 60 centimeters of the wearable electronicdevice 2306. In some examples, the body-worn repeater 2304 may belocated within the range of 0.1 millimeters to 30 centimeters of thewearable electronic device 2306.

Generally, a coil included in the body-worn repeater 2304 for receivingpower from the base unit 2302 may be larger than a coil included in thewearable electronic device 2306 used to receive power from the body-wornrepeater 2304. For example, a diameter of the coil used in the body-wornrepeater 2304 for receiving power from the base unit 2302 may be largerthan a diameter of a coil in the electronic device 2306 used to receivepower from the body-worn repeater 2304. For example, a length, width, orboth, of the coil used in the body-worn repeater 2304 for receivingpower from the base unit 2302 may be larger than a length, width, orboth of a coil in the electronic device 2306 used to receive power fromthe body-worn repeater 2304. A repeater having multiple coils may bedesigned to have optimum transfer of wireless power between the coils.In some examples, multiple coils may be implemented having a commoncore. The larger size of the coil used to receive power from the baseunit may relax requirements on the base unit for power transmission. Forexample, it may not be necessary for the base unit to provide wirelesspower to a coil as small as the coil provided in the wearable electronicdevice (e.g. on the order of millimeters in some examples, on the orderof a few centimeters in other examples). Instead, the base unit in someexamples need only provide power to the larger coil provided in thebody-worn repeater. The body-worn repeater may be larger (e.g. on theorder of centimeters or more in some examples).

Generally, wireless power may be transmitted from the base unit 2302 tothe body-worn repeater 2304 and from the body-worn repeater 2304 to thewearable electronic device 2306 using a body safe frequency. In someexamples, a frequency of between 100 kHz and 130 kHz may be used. Insome examples, a frequency of 125 kHz+/−2 kHz may be used. In someexamples, a frequency of 125 kHz+/−3 kHz may be used. In sonic examples,a frequency of 125 kHz+/−5 kHz may be used.

A single wearable electronic device 2306 is shown in FIG. 23, However,more than one wearable electronic device 2306 may be present in examplesystems and may receive wireless power from the body-worn repeater 2304.Example systems may include a plurality of wearable electronic devices,each of the plurality of wearable electronic devices including arespective coil to receive wireless power from the body-worn repeater2304.

A single body-worn repeater 2304 is shown in FIG. 23, However, it is tobe understood in some example systems, more than one body-worn repeater2304 may be used—including, but not limited to 2, 3, 4, or 5 body-wornrepeaters. Each body-worn repeater may in turn provide wireless power toanother body-worn repeater, and ultimately at least one of the body-wornrepeaters may provide wireless power to a particular wearable electronicdevice.

Example devices described herein may include coils integral in asupporting member (e.g. a band, cord, housing). The supporting membermay at least partially define one or more apertures or be shaped toreceive or house an electronic device. In some examples, an electricalconnection may be provided between the coil and the electronic device(e.g. the aperture may present one or more electronic connections to anelectronic device). In some examples, an electrical connection may beprovided between the coil and the electronic device simply by theproximate presence of the electronic device to the coil—for example, thecoil may be inductively coupled to the electronic device when theelectronic device is present in the aperture.

FIG. 24 is a schematic illustration of a band that may include arepeater and/or wearable electronic device in accordance with examplesdescribed herein.

The device 2400 includes a band 2406, coil 2402, and aperture 2404. Theband 2406 defines the aperture 2404.

The band 2406 may be implemented, for example, by a wrist band, watchband, fitness monitor band, lag band, arm band, head band, bracelet,necklace, ring or other wearable item.

The coil 2402 may be integrated in the band 2406, for example, by beingburied in the band, supported by the band, attached to the band, orother integration mechanism. In some examples, the coil 2402 may beimplemented as an antenna. Antennas described herein may be implementedusing omnidirectional and/or phased array antennas.

The band 2406 may define an aperture 2404. The aperture 2404 may besized to house, contain, or support an electronic device. For example,an electronic device may be snapped into the aperture 2404. Whenpositioned in the aperture 2404 (e.g. “snapped in”), the electronicdevice may be in communication with the coil 2402, through direct orindirect electrical connection. In this manner, the coil 2402 may insome examples serve as an antenna for the wearable electronic device2306. In some examples, the band 2406 with the coil 2402 may be used toimplement a repeater described herein, such as the body-worn repeater2304 of FIG. 23. In some examples, one or more circuits used to operatethe repeater may be contained in the aperture 2404.

While the band 2406 is shown as defining aperture 2404 in FIG. 24, insome examples, supporting members may define a cavity for housing anelectronic device, may include a recess for housing an electronicdevice, may include an attachment mechanism for attaching to anelectronic device, and/or may define a recess or indentation for housingan electronic device.

The band 2406 may be made out of any material. The band 2406 may be madein some examples out of a hypoallergenic material.

While a single aperture 2404 is shown in FIG. 24 for containing a singleelectronic device, in other examples bands or other supporting membersmay house, support, or attach to multiple electronic devices.Accordingly, in some examples, multiple apertures may be provided by theband 2406 in some examples.

An electronic device placed in the aperture 2404 may be charged via thecoil 2402 in the band 2406 via conventional conductive charging wherethe physical interface between the band 2406 and electronic device mayinclude a split metal wring with each component of the wring being apositive or negative electrode. In some examples the electronic deviceplaced in the aperture 2404 may be charged via the use of inductivecoupling between the charging interface of the electronic device and theband 2406. This coupling may in some examples be optimized given thatthe loads and exact positions of the coils in each device may be fixed.The position and load within an electronic device may be specified in anintegrated circuit design (ICD) for the band 2406.

The coil 2402 of the band 2406 may be charged from a base unit (e.g. thebase unit 2302 of FIG. 23) via wireless power transfer, examples ofwhich are described herein. In some examples, the base unit (e.g. Baseunit 2302) may include a proximity sensor which may provide the positionand approximate orientation of the band 2406 with respect to the baseunit. The load on a resonator in the base unit may then be dynamicallyadjusted to as to maximize and/or increase resonant coupling between thetwo units. A predictive algorithm may operate on a micro controller inthe base unit to estimate the relative motion of the band with respectto the base unit and apply corrections to the dynamic load in the baseunit resonator.

The device 2400 may be implemented as a repeater separate from theelectronic wearable device or an antenna that is connected to theelectronic wearable device.

FIG. 25 is a flowchart illustrating a method arranged in accordance withexamples described herein.

A method 2500 may include positioning a base unit proximate a body-wornrepeater 2502, wirelessly transmitting power from the base unit to thebody-worn repeater 2504, and wirelessly transmitting power from thebody-worn repeater to a wearable electronic device 2506.

The method 2500 may be implemented using the system 2300 of FIG. 23,and/or the device 2400 of FIG. 24.

In some examples, positioning a base unit proximate a body-worn repeater2502 may be implemented using a base unit, such as the base unit 2302 ofFIG. 23, The base unit may include a transmitting coil for wirelesslytransmitting power to a receiving coil of the body-worn repeater. Insome examples, positioning a. base unit proximate a body-worn repeater2502 includes positioning the base unit such that a distance between thebase unit and the body-worn repeater is less than a charging range ofthe base unit.

Generally, charging range refers to a distance at which power ismeaningfully being transferred from one device to another.

In some examples, positioning a base unit proximate a body-worn repeater2502 includes wearing the base unit. For example, the base unit may beworn on a belt, necklace, armband, leg band, mobile phone or othercommunication system, hat, clothing, or combinations thereof. The baseunit in some examples may be carried in a briefcase, hand, purse,pocket, backpack, or combinations thereof. The base unit in someexamples may be implemented using a case attached to a mobile phone orother communication system. In some examples positioning a base unitproximate a body-worn repeater 2502 may include positioning a base unitin a room, automobile, aircraft, or other location near a user.

In some examples, the body-worn repeater may be implemented in or as aring, watch, bracelet, necklace, earring, hair band, hair clip, shoe,belt, broach, clip, hat, helmet, band, strap, or combinations thereof.

In sonic examples, the method 2500 may include housing or attaching thewearable electronic device in or to the body-worn repeater. For example,the body-worn repeater may define an aperture, such as the device 2400,for receiving the wearable electronic device. The wearable electronicdevice may be snapped into or attached to or placed into the body-wornrepeater.

In some examples, wirelessly transmitting power from the base unit tothe body-worn repeater 2504 includes wirelessly transmitting power fromthe base unit to the body-worn repeater while the base unit remainswithin the charging range of the body-worn repeater.

In some examples, wearable electronic device 2306 of FIG. 23 may be usedto implement the method 2500. The wearable electronic device may includea receiving coil.

In sonic examples, a distance between the body-worn repeater and thewearable electronic device is smaller than a distance between the baseunit and the wearable electronic device.

In sonic examples, wirelessly transmitting power from the body-wornrepeater to a wearable electronic device 2506 may include wearing thewearable electronic device within a distance less than a charging rangeof the body-worn repeater from the body-worn repeater. For example, thebody-worn repeater may be worn as a necklace, and the wearableelectronic device may be worn on or around the head, neck, or shoulderswhile the base unit may be positioned or worn about the waist or lowerbody. Wirelessly transmitting power from the body-worn repeater to awearable electronic device 2506 may include energizing the coil in thewearable electronic device with the coil of the body-worn repeater.

In some examples, wirelessly transmitting power from the base unit tothe body-worn repeater 2504 may include bringing the body-worn repeaterand wearable electronic device within a distance less than a chargingrange of the body-worn repeater from the body-worn repeater. Forexample, a necklace, armband, wristband, or watch including thebody-worn repeater may be lifted closer to a wearable electronic deviceby, for example, moving the necklace with a user's hand, or bringing auser's arm in closer proximity to the wearable electronic device e.g.nearer the head, neck, or shoulders).

In some examples, methods include wirelessly transmitting power from thebody-worn repeater to a plurality of wearable electronic devices. Theplurality of wearable electronic devices may include respective furtherreceiving coils, and the further receiving coils of the wearableelectronic devices may each be smaller than the receiving coil of thebody-worn repeater. The distance between certain or all of the wearableelectronic devices and the body-worn repeater may be smaller than adistance between certain or all of the wearable electronic devices andthe base unit.

The method 2500 may include wearing the body-worn repeater and wearingor carrying the base unit and wearable electronic device.

FIG. 26 is a schematic illustration of a system arranged in accordancewith examples described herein. The system 2600 may include atransmitter 2602 and a receiver 2604. The transmitter 2602 may include atransmitter coil 2606, circuitry 2610, and a battery 2614. The receiver2604 may include a receiver coil 2608 and circuitry 2610. Thetransmitter 2602. receiver 2604, and/or system 2600 may includeadditional components in some examples. For example, the transmitter2602 may include an antenna. Multiple antennas and/or coils may beincluded in the transmitter 2602 in some examples.

The transmitter 2602 may serve to provide wireless power to the receiver2604. Generally, the transmitter 2602 may be implemented using any baseunit described herein. The receiver 2604 may be implemented using anyelectronic device described herein, including a wearable electronicdevice such as but not limited to a camera, sensor, or hearing aid.While a single receiver 2604 is shown in FIG. 26, any number ofreceivers may be used in the system 2600. The transmitter 2602 mayprovide wireless power to one or more receivers in the system 2600. Insome examples, one or more receivers may provide data or other signalsback to the transmitter 2602.

The transmitter 2602 includes a transmitter coil 2606, circuitry 2610,and battery 2614. The transmitter may have any form factor. For example,example base units described herein may be implemented in a case for amobile communication device, such as a cell phone. In other examples,the transmitter 2602 may be included in housing and used to powerdevices. The transmitter 2602 may for example be implemented in ahousing having a thin, circular form factor e.g. similar to a make-upcompact). In some examples, a housing used to implement the transmitter2602 may have an indent, cavity, or other receiving surface forsupporting a receiver, such as the receiver 2604 in examples Where thereceiver 2604 may be placed into or on the transmitter 2602. Generally,however, there may be distance separation between the transmitter coil2606 and receiver coil 2608.

The transmitter 2602 may transmit power between 1 microwatt to 100 wattsin some examples. In some examples, when transmitting to an electronicwearable device receiver that may be worn on a human body, thetransmitted energy may be 10 watts or less. Generally, an amount ofpower transmitted may be less than limits set by regulatory authorities,such as the FCC, for RF energy exposure. For example, the amount ofpower transmitted may be less than 0.08 Watts per kilogram of the userin some examples, less than 0.4 Watts per kilogram of the user in someexamples, less than 1.6 Watts per kilogram of the user in some examples,and less than 8 Watts per kilogram of the user in some examples. In someexamples, a strength of the magnetic field used at a particularfrequency may be less than or equal to limits allowed by regulation—e.g.ETSI-30 regulation compliant. For example, ETSI-30 regulations may allowfor 6 dBμA/m at 10 m at frequencies between 119 to 135 kHz.

The transmitter coil 2606 may be implemented using a magnetic metal core(e.g. a rod of magnetic material) in a wire winding. The magnetic metalcore may be implemented using a ferrite material. The magnetic metalcore may be shaped with its length longer than its width. The magneticmetal core may be shaped with its length longer than its diameter. Thewire winding may be implemented using, for example, stranded wire. Litzwire and/or copper wire. Litz wire generally refers to wire thatincludes many thin wire strands, individually isolated and woventogether. Litz wire can be used to reduce resistive losses in someexamples due to skin effect or proximity effect in a coil, This mayallow in some examples for higher Q values. Examples of transmittingcoils described herein (e.g. with reference to FIGS. 15A-15C and FIGS.16A-16C) may be used to implement the transmitter coil 2606.

In some examples, the transmitter coil 2606 may be implemented using oneor more planar (e.g. flat) coils adjacent to one or more planar (e.g.flat) magnetic material structures. The distance separated receiver(e.g. receiver coil 2608) can use a coil wire wound around a magneticmaterial core. The magnetic material core can be, by way of exampleonly, in the shape of a rod.

The battery 2614 may store power for transmission by the transmittercoil 2606. In some examples, the battery 2614 may receive a charge froma wired connection during a charging mode of the transmitter 2602. Insome examples, the transmitter 2602 may include energy harvestingcircuitry and/or sensors which may charge the battery 2614 using energyharvested from the environment (e.g. solar, wind, vibrational, and/orthermal energy).

The circuitry 2610 may control power transmission from the transmittercoil 2606. The circuitry 2610 may have an impedance which may, in someexamples, be adjustable. Generally, the transmitter 2602 may have animpedance (e.g. an impedance of the transmitter coil 2606 and circuitry2610). The impedance of the transmitter 2602 may in some examples beadjusted by selecting and/or adjusting the impedance of the circuitry2610. The circuitry 2610 may have an impedance set by one or moreinductive element(s), such as inductor(s), capacitive element(s), suchas capacitor(s), and/or resistive element(s), such as resistor(s). Anyor all of those elements may be adjustable. In some examples, thecircuitry 2610 may include a tuning capacitor comprising a dielectricmaterial.

The load (e.g. impedance) and/or the frequency provided by thetransmitter (e.g. in base station) may then be dynamically adjusted insome examples so as to improve or maximize resonant coupling between thetwo transmitter and receiver. This process may be referred to asadaptive tuning. The transmitter 2602 may include a microcontroller orother processing unit(s) (e.g. processors) which may execute apredictive algorithm to estimate relative motion of the receiver withrespect to the transmitter and apply corrections to the dynamic load orfrequency in the transmitter. In some examples, a proximity sensor maybe provided in the transmitter 2602 or other example base stations. Theproximity sensor may detect a position and approximate orientation ofthe receiver with respect to the transmitter for use in tuning and/orapplying corrections in the transmitter the power coupling. Generallyany components that can tune the electromagnetic frequency, itsamplitude or its phase by altering its reactance, resistance,capacitance or inductance may be used. For example, one or more ASICs.The tuning process may be controlled by a signal analyzer that maymonitor and analyze signals from a sensor or sensors that detectdistance between the transmitter and the receiver, the relativealignment between the transmitter and the receiver (e.g. alignmentbetween magnetic cores of the transmitter and the receiver), and/orchanges in electrical characteristics of the electrical circuits of thetransmitter and the receiver that may be caused for example byintroduction or withdrawal of electrical power sources or sinks (e.g.loads) in the transmitter or the receiver (e.g. repeater and/orelectronic wearable device).

In some examples both the transmitter and the receiver (e.g. repeaterand/or wearable device) may be moving (e.g. moving relative to oneanother). In some examples, processing unit(s), such as ASICs and/or oneor more embedded processors, may be provided in one or both of thetransmitting and receiving devices to estimate relative motion. Thedevices may include additional sensors for estimating motion including.,but not limited to) accelerometers, gyroscopes, inertial measurementunits, or ranging devices (ultrasonic, optical, or otherwise).Algorithms which estimate motion and relative motion may include (butare be limited to) Kalman filters, extended Kalman filters,Savitzky-Golay filters, phase-lock loops, time of flight estimators,phase estimators, and coherent interferometric processing.

Alignment of transmitters and receivers (e.g. of the magnetic core oftransmitting and receiving coils described herein) may, by way ofexample only, be effected through the use of a coil array on thetransmitter (e.g. base unit), use of phased antenna arrays on thetransmitter (e.g. base unit) and receiver (e.g. repeater and/or wearableelectronic device), alignment of coils or antennas via the use ofpiezoelectric devices or other similar devices, or via direction to theuser by way of an indicator. Accordingly, base units, transmitters,and/or receivers described herein may be provided with an indicator(e.g. a light, speaker) that provides an indication (e.g. a light orsound) based on the proximity and/or relative angle between thetransmitter and receiver (e.g. between magnetic cores of transmit andreceive coils described herein). For example, the transmitter may beoptimized to provide power transfer at a particular angle and/ordistance to the receiver, and circuitry and/or processing unit(s) may beprovided to control the indicator to provide an indication when thetransmitter and receiver are within the particular angle and/or distancefor power transfer, which may be a range.

The receiver coil 2608 may be implemented using a magnetic metal core(e.g. a rod of magnetic material) in a wire winding. The magnetic metalcore may be implemented using a ferrite material. The magnetic metalcore may be shaped with its length longer than its width. The magneticmetal core may be shaped with its length longer than its diameter. Thewire winding may be implemented using, for example, stranded wire, Litzwire and/or copper wire. Examples of coils described herein may be usedto implement the receiver coil 2608. Example sizes for the receiver coil2608 include 20 mm length×3 mm diameter in some examples, 40 mm lengthby 6 mm diameter in some examples, 80 mm length×12 mm diameter in someexamples.

The receiver coil 2608 may be implemented using one or more planar(e.g., flat) coils adjacent to one or more planar (e.g. flat) magneticmaterial structures and the distance separated transmitter (e.g.transmitter coil 2606) may be implemented using a coil wire wound arounda magnetic material core. The magnetic material core can be, by way ofexample only, in the shape of a rod.

The circuitry 2612 may control receipt of power transmitted by thetransmitter coil 2606 by the receiver coil 2608. Generally, the receiver2604 may have an impedance (e.g. an impedance of the receiver coil 2608and circuitry 2612). The impedance of the transmitter 2602 may in someexamples be adjusted by selecting and/or adjusting the impedance of thecircuitry 2612. The circuitry 2612 may have an impedance set by one ormore inductive element(s), such as inductor(s), capacitive element(s),such as capacitor(s), and/or resistive element(s), such as resistor(s).Any or all of those elements may be adjustable. In some examples, thecircuitry 2612 may include a tuning capacitor comprising a dielectricmaterial.

The receiver 2604 and transmitter 2602 (e.g. the receiver coil 2608 andtransmitter coil 2606) may be separated by a distance in accordance withexamples described herein. The distance may be on the order ofmillimeters in some examples, centimeters in some examples, meters insonic examples.

Generally, the transmitter coil 2606 may be larger than the receivercoil 2608 in some examples, such that a base unit may be used to chargea relatively small device (e.g. a wearable electronic device). In sonicexamples, the transmitter magnetic metal core of transmitter coil 2606has a volume that is 10 times or larger than a volume of the magneticmetal core of the receiver coil 2608, 100 times or larger than thevolume of the magnetic metal core of the receiver coil 2608 in someexamples, 1000 times or larger than the volume of the magnetic metalcore of the receiver coil 2608 in some examples. In sonic examples, thewire winding of the transmitter coil 2606 has a winding length that is10 times or larger than a winding length of the wire winding of thereceiver coil 2608, 100 times or larger than a winding length of thewire winding of the receiver coil 2608 in some examples, or 1000 timesor larger than a winding length of the wire winding of the receiver coil2608 in some examples.

The system 2600 may in some examples advantageously transmit and receivepower at body-sate frequencies. In some examples, the transmitter 2602is configured to transmit wireless power at a frequency in a range of100 kHz to 200 kHz. In some examples, the transmitter 2602 is configuredto transmit wireless power at a frequency within a range of 125 kHz+/−3kHz. In sonic examples, the transmitter 2602 is configured to transmitwireless power at a frequency within a range of 125 kHz+/−5 kHz may beused. in some examples, the transmitter 2602 is configured to transmitwireless power at a frequency within a range of 6.75 MHz+/−5 MHz. Byoperation at a particular frequency (e.g. transmission of power at aparticular frequency), in some examples refers to the use of a carrierfrequency at the specified frequency or frequency range by the circuitry2610 and/or circuitry 2612. Inverter circuits may be included in thecircuitry 2610 and/or circuitry 2612 to achieve operation at thespecified frequency and/or frequency ranges.

In some examples, the transmitter impedance and the receiver impedanceare optimally matched for a particular distance separation between thetransmitter and the receiver, and non-optimized for all other separationdistances. By optimally matched, in some examples, the efficiency ofpower transfer may peak (e.g. be above 95%, above, 90%, above 85%, above80%, or other thresholds in other examples) at the particular separationdistance. The transmitter impedance and receiver impedance may beselected to optimally match during power transfer at the particulardistance. The particular distance may be selected, for example, inaccordance with a typical use case for the transmitter 2602 and/orreceiver 2604. For example, the particular distance may be selectedbased on a distance between the transmitter coil 2606 and receiver coil2608 that may be expected during normal use (e.g. if the transmitter2602 is designed for placement on a table, and the receiver 2604 isdesigned for placement within a particular distance, that may be theparticular distance used for optimally matching the impedance). Inanother example, if the transmitter 2602 is designed to be worn at onelocation, e.g. a user's belt, and the receiver 2604 is designed to beworn at a second location, e.g. a user's eyewear, the particulardistance may be equal to a typical distance between the first and secondlocations (e.g. the distance between the user's belt and eyewear, or atypical user's belt and eyewear).

Generally, power transfer efficiency may be a function of the Q valuesof the transmitter 2602 and receiver 2604. The power transfer efficiencymay be given as:

$\eta = \frac{k^{2} \cdot Q_{1} \cdot Q_{2}}{\left( {1 + \sqrt{1 + {k^{2} \cdot Q_{1} \cdot Q_{2}}}} \right)^{2}}$

where Q₁ is the Q value of the transmitter 2602, Q₂ is the Q value ofthe receiver 2604, and k is the coupling coefficient. Generally, thestronger the coupling in this example, the higher the transferefficiency of the system 2600. Efficiency may be dependent in examplesof the system 2600 on a ratio of distance between the transmitter coil2606 and receiver coil 2608 and the coil sizes. Generally, the system Qvalue may be a geometric mean of the Q values of the transmitter 2602and receiver 2604.

In some examples, the transmitter impedance and the receiver impedancemay be optimally matched for at least two particular distanceseparations between the transmitter and the receiver, and non-optimizedfor all other separation distances. The impedance may be optimallymatched for two particular distances in some examples, three particulardistances in some examples, or another number of distances in otherexamples. By optimally matched, in some examples, the efficiency ofpower transfer may peak (e.g. be above 95%, above, 90%, above 85%, above80%, or other thresholds in other examples) at the particular separationdistance. The circuitry 2610, circuitry 2612, or both, may have at leasttwo settings to achieve optimal impedance matching at the at least twodistances (e.g. one set of settings may be used at one distance andanother at a second distance). Other sets of settings may be used whereadditional distances may be optimally matched. To select an appropriateimpedance value, the circuitry 2610, circuitry 2612, or both may selectV attics for adjustable elements of the circuitry (e.g. adjustablecapacitor(s)) to attain the desired impedance value.

The particular distances may be selected, for example, in accordancewith a typical use case for the transmitter 2602 and/or receiver 2604.For example, where the transmitter 2602 is positioned at a. firstposition (e.g. a user's belt), the receiver 2604 may typically be foundin a number of different distances from the first position (e.g. whenthe receiver 2604 is implemented using a camera, the receiver 2604 maybe positioned at some times on eyewear of the user worn on the face at afirst distance from the first position, and may be positioned at othertimes, for example, in a pocket of the user at a second distance fromthe first position). The circuitry 2610, circuitry 2612, or combinationsthereof may adjust their impedance based, for example, on a sensorreading indicative of distance between the transmitter 2602 and receiver2604. For example, the circuitry 2610, circuitry 2612, or both may haveone impedance value for use at one distance and another impedance valuefor use at another distance.

In some examples, the transmitter impedance and the receiver impedancemay be optimally matched for a plurality of separation distances usingautomatic iterative impedance optimization. For example, the circuitry2610, circuitry 2612, or both may implement automatic iterativeimpedance optimization.

In some examples, the transmitter impedance and the receiver impedancemay be optimally matched for a particular relative orientation betweenthe transmitter 2602 and the receiver 2604 (e.g. between the transmittercoil 2606 and the receiver coil 2608), and non-optimized for all otherrelative orientations. By optimally matched, in some examples, theefficiency of power transfer may peak (e.g. be above 95%, above. 90%,above 85%, above 80%, or other thresholds in other examples) at theparticular relative orientation. The transmitter impedance and receiverimpedance may be selected to optimally match during power transfer atthe relative orientation. The particular relative orientation may beselected, for example, in accordance with a typical use case for thetransmitter 2602 and/or receiver 2604. For example, the particularrelative orientation may be selected based on a distance between thetransmitter coil 2606 and receiver coil 2608 that may be expected duringnormal use (e.g. if the transmitter 2602 is designed for placement on atable, and the receiver 2604 is designed for placement relative to thetransmitter in a certain location, the resulting orientation may be theparticular relative orientation used for optimally matching theimpedance). In another example, if the transmitter 2602 is designed tobe worn at one location, e.g. a user's belt, and the receiver 2604 isdesigned to be worn at a second location, e.g. a user's eyewear, theparticular relative orientation may be the orientation typicallyexpected from devices positioned at the first and second locations (e.g.the relative orientation between devices positioned at the user's beltand eyewear, or a typical user's belt and eyewear).

In some examples, the transmitter impedance and the receiver impedancemay be optimally matched for at least two particular relativeorientations between the transmitter and the receiver, and non-optimizedfor all other relative orientations. The impedance may be optimallymatched for two relative orientations in some examples, three relativeorientations in some examples, or another number of relativeorientations in other examples. By optimally matched, in some examples,the efficiency of power transfer may peak (e.g. be above 95%, above,90%, above 85%, above 80%, or other thresholds in other examples) at theparticular relative orientations. The circuitry 2610, circuitry 2612, orboth, may have at least two settings to achieve optimal impedancematching at the at least two relative orientations (e.g. one set ofsettings may be used at one relative orientation and another at a secondrelative orientation). Other sets of settings may be used whereadditional relative orientations may be optimally matched. To select anappropriate impedance value, the circuitry 2610. circuitry 2612, or bothmay select values for adjustable elements of the circuitry (e.g.adjustable capacitor(s)) to attain the desired impedance value.

The particular relative orientations may be selected, for example, inaccordance with a typical use case for the transmitter 2602 and/orreceiver 2604. For example, where the transmitter 2602 is positioned ata first position (e.g. a user's belt), the receiver 2604 may typicallybe found in a number of different positions relative to the firstposition (e.g. when the receiver 2604 is implemented using a camera, thereceiver 2604 may be positioned at some times on eyewear of the userworn on the face in a first relative orientation from the firstposition, and may be positioned at other times, for example, in a pocketof the user at a second relative orientation from the first position).The circuitry 2610, circuitry 2612, or combinations thereof may adjusttheir impedance based, for example, on a sensor reading indicative ofthe relative orientation between the transmitter 2602 and receiver 2604.For example, the circuitry 2610, circuitry 2612, or both may have oneimpedance value for use at one relative orientation and anotherimpedance value for use at another relative orientation.

In some examples, the transmitter impedance and the receiver impedancemay be optimally matched for a plurality of relative orientations usingautomatic iterative impedance optimization. For example, the circuitry2610, circuitry 2612, or both may implement automatic iterativeimpedance optimization. A variety of circuit techniques may be employedto achieve iterative impedance optimization, including but not limitedto tapping and/or active circuit approaches.

In some examples, the transmitter impedance and the receiver impedancemay be adjusted automatically, for example, using an actuator controlledby an algorithm (e.g. using a controller, custom circuitry, and/orprogrammed computing system) to a preset or target value(s) required foroptimum transfer efficiency at a particular distance or particularorientation. The algorithm may be implemented using firmware or on boardsoftware in the transmitter and receiver electronics, including forexample, an ASIC, a microcontroller or a programmable field array. Thepreset or target value(s) may be stored in a look up table used by thealgorithm.

In some examples, the transmitter and the receiver may be provided withtelemetry capability so that the transmitter and the receiver maywirelessly exchange information on their location and/or orientation.This data may then be used by the optimization program to compute theimpedances of the transmitter and the receiver circuits for optimumwireless transfer efficiency between the transmitter and the receiver.In some examples, this optimization program may include an automaticiterative impedance optimization.

The receiver 2604 and transmitter 2602 may be loosely coupled.

Generally speaking, wireless energy transfer between transmitters andreceivers involves far field transfer in which the distance between thetransmitter and the receiver is a large numerical multiple of thewavelength of the electromagnetic energy being used to effect thewireless energy transfer process. In some examples, the distance betweenthe transmitter and the receiver is also a large multiple of thediameter or length of the coil inside the receiver.

The system 2600 may be a weak resonant system having a Q value below100. In some examples, however, the Q value may be above 100. The systemQ value may be the geometric mean of the Q values of the transmitter2602 and receiver 2604 (e.g. the Q value of the transmitter coil 2606and/or circuitry 2610 for the transmitter 2602 and the Q value of thereceiver coil 2608 and/or circuitry 2612 for the receiver 2604). SystemQ value may be influenced by resistive losses in the circuitry 2610and/or circuitry 2612. The system Q value may be selected by selectingan appropriate wire and winding scheme for the transmitter coil 2606and/or receiver coil 2608. Generally, weakly resonant systems have lowersystem Q-factors than highly resonant systems. A Q-value may be selectedto achieve a weak resonant system (e.g. Q less than 100).

Weakly resonant may refer to examples where the transmitter and theseparated receiver of a wireless power transfer system are not impedancematched, but are designed to resonate at the same frequency, whereby thewireless power system utilizes a Q value that is less than 100 and incertain cases less than 50, and is some less than 10.

FIG. 27 is a schematic illustration of four transmitter designs arrangedin accordance with examples described herein. Generally, multiple oftransmitter coils (e.g. magnetic cores) may be used in exampletransmitters described herein. Providing multiple transmitter coils eachwith a different orientation may, in some examples, improve orientationindependence of example systems described herein.

Wireless charging with single sources may in some examples create adegree of orientation dependence. While the use of wire wound ferritecores in examples described herein may produce a reasonable magneticfield distribution for charging, even good single source transmitter mayhave some remaining degree of directional dependence. Accordingly, theuse of multiple transmitters may aid in reducing orientation dependenceof the wireless power delivery capability in some examples.

Examples described herein may provide weakly resonant wireless powersystems having multiple transmitting coils—each transmitting coil may beimplemented using a wound ferrite core as described herein. Weaklyresonant may generally be used herein to refer to the transmitter andthe separated receiver of a wireless power transfer system being notimpedance matched, but designed to resonate at a same frequency, suchthat the wireless power system utilizes a Q value that is less than 100in some examples, less than 50 in some examples, and less than 10 insome examples. The multiple transmitting coils may be driven to producean improved omnidirectional radiation pattern over time. Such a systemmay allow a receiving system to be largely orientation insensitive, orhave improved orientation insensitivity, since the receiver coils may besignificantly smaller than the transmitter coils used in exampletransmitters described herein. The small receiving coil (e.g. wire woundferrite core receiver) may be considered to be essentially immersed in arotating magnetic field provided by the larger transmitter coils. Thismay allow the receiver to have a wide range, or improved range, oforientations relative to the transmitter and still receive a significantamount of energy from the transmitter.

Example transmitters may include at least two wire wound ferromagneticcores magnetic coils placed in a position in space in a predefinedorientation and driven in a phased manner to eliminate and/or reduce theunidirectionality of the magnetic field while creating a rotatingmagnetic field over time.

The transmitter 2702 includes a battery 2704 and coil 2706, coil 2708,and coil 2710. The coils 2706, 2708, and 2710 have rod-shaped coresarranged to extend radially away from a center of the transmitter 2702,with each rod-shaped core spaced 120 degrees from the other. The coils2706, 2708, and 2710 may be implemented using wire wound ferrite coresources described herein. The coils 2706, 2708, and 2710 may be placedover a single power source, such as, by way of example only, arechargeable battery 2704. The coils 2706, 2708, and 2710 may be drivenin a sequenced fashion so as to prevent an approximately staticuni-directional magnetic field pattern that may result if the sourceswere driven in phase.

FIG. 31 is a schematic illustration of driving sequences that may beused to drive the transmitter designs shown in the example of FIG. 27arranged in accordance with examples described herein. For example, thedriving sequence 3102 may be used to drive the coils of the transmitter2702. The driving sequence 3102 illustrates driving signals provided tothe coils 2706, 2708, and 2710. Sequences pulses, square waves in theexample of FIG. 31, although other pulse shapes may be used, areprovided to the coils 2706, 2708, and 2710. In some examples, the pulsesare sequenced such that the pulse delivered to each coil 2706, 2708, and2710 does not overlap in time, however in some examples an overlap maybe present. Generally, however, the driving sequence 3102 may beselected to provide a generally omnidirectional and/or rotating field,or field having improved omnidirectionality and/or rotation. In someexamples, the peak of the driving signal provided to each of the threecoils in the example of transmitter 2702 may be provided at differenttimes.

The transmitter 2712 includes a battery 2714 and coil 2716 and coil2718. The coils 2716 and 2718 may be implemented using wire woundferrite core sources described herein. The two coils 2716 and 2718 maybe placed on either side of the power source, here battery 2714. Thecoils 2716 and 2718 are oriented parallel to one another and spacedapart in the transmitter 2712. The coils 2716 and 2718 may be driven ina sequenced manner. A driving sequence 3104 is shown in FIG. 31 fordriving the coils 2716 and 2718. Sequences pulses, square waves in theexample of FIG. 31. although other pulse shapes may be used, areprovided to the coils 2716 and 2718. In some examples, the pulses aresequenced such that the pulse delivered to each coil 2716 and 2718 doesnot overlap in time, however in some examples an overlap may be present.Generally, however, the driving sequence 3104 may be selected to providea generally omnidirectional and/or rotating field, or field havingimproved omnidirectionality and/or rotation. In some examples, the peakof the driving signal provided to each of the two coils in the exampleof transmitter 2712 may be provided at different times.

The transmitter 2720 includes a battery 2722 and coil 2724 and coil2726, The coils 2724 and 2726 may be implemented using wire woundferrite core sources described herein. The two coils 2724 and 2726 maybe placed on a power source, here battery 2714, The coils 2724 and 2726are oriented 90 perpendicularly to one another. The coils 2724 and 2726are shown as aligning along one edge of the coils 2724 and 2726, howeverin another example, the coil 2724 may be positioned to extend from amiddle portion of the coil 2726, or vice versa. The coils 2724 and 2726may be driven in a sequenced manner. A driving sequence 3106 is shown inFIG. 31 for driving the coils 2724 and 2726. Sequences pulses, squarewaves in the example of FIG. 31, although other pulse shapes may beused, are provided the coils 2724 and 2726. In some examples, the pulsesare sequenced such that the pulse delivered to each coil 2724 and 2726does not overlap in time, however in some examples an overlap may bepresent. Generally, however, the driving sequence 3106 may be selectedto provide a generally omnidirectional and/or rotating field, or fieldhaving improved omnidirectionality and/or rotation, in some examples,the peak of the driving signal provided to each of the two coils in theexample of transmitter 2720 may be provided at different times.

The transmitter 2728 includes a battery 2730 and coil 2732 and coil2734. The coils 2732 and 2734 are oriented perpendicular to one anotherand overlapping at a central section. The coils 2732 and 2734 may beimplemented using wire wound ferrite core sources described herein. Insome example, the coils 2732 and 2734 may be formed using a single,cross-shaped core. The coils 2732 and 2734 may be placed on a powersource, here battery 2714.

Other coils configurations may be used in other examples including 4coils placed around the four sides of a power source and driven out ofphase or sequenced in an analogous manner as described with reference tothe configurations of FIG. 27 and FIG. 31, Another example includes twocoils placed in a 90-degree cross pattern and driven 90 degrees out ofphase with one another (e.g. as shown in transmitter 2728).

All coils shown in FIG. 27 may be implemented using a core of a magneticmaterial (e.g. ferrite) included in a wire winding (e.g. stranded wire,Litz wire, copper wire, or combinations thereof).

Generally, the receiving coils used to receive power from thetransmitters shown in FIG. 27 may be significantly smaller than thecoils used in the transmitters. The coupling between the transmitter andreceiver coils may be only loosely coupled as described herein and theoverall size of each coil (e.g. transmitter and receiver) may be reducedby using a magnetic (e.g. ferrite) core. The wireless power system mayhave a Q value that is less than 100, in some cases less than 50, and insome cases less than 10. Accordingly, example wireless power systemsdescribed herein may be weakly resonant.

Transmitter and/or receiver designs may be optimized by selecting amaterial (e.g. ferrite) core material permeability, a core size, anumber of windings, and a wire type to produce a desired inductancealong with a selected capacitance to produce a resonant receiver ortransmitter coil. This can be described in the expression2πF=1/sqrt(L*C).

Where L is the inductance, C is the capacitance of the system and F isthe resonant frequency.

In this manner, resonant LC circuits on the transmitter and receiverside may be provided. In some examples, the capacitance may be chosenbased on the coil inductance, by way of example only, at a resonancefrequency at or near 125 kHz. In some examples, a resonance frequency of125 kHz+/−3 kHz may be used. In some examples, a resonance frequency of125 kHz+/−5 kJz may be used. Other frequencies may be used as describedherein. The inductance and the capacitance may be different fortransmitter and receiver, but they are chosen so that both transmitterand receiver may have resonance at the design frequency, by way ofexample only, at or near 125 kHz. In certain different embodiments therange of the design frequency can he within the range of 100 kHz to 130kHz.

The described component selected may be performed even if the transmitand receiver coils are significantly different in size, which may occurin examples described herein where the receiver coil may besignificantly smaller such that it may be placed, e.g. in an electronicwearable device. Since the system is operating in the near-field, thesize of the coil may not have to match with the wavelength of thetransmitted energy and as such both the transmitter and receiver coilsmay be quite small relative to the wavelength of the transmittedfrequency. However, in some examples the transmit coils may hesignificantly larger than the receiver coils. This may allow foropportunities for charging and for charging multiple devices with thesame transmitter coil or coils.

Accordingly, one or more transmit and receive coils in systems describedherein may be designed to be in resonance at a predetermined frequency(e.g. through selection of the inductance, capacitance, and/orresistance provided by the coil and/or to the coil). The predeterminedfrequency may be the same in the transmit coils and the receiving coilsof the system in sonic examples. The frequency of the driving waveform(e.g. the frequency of the pulses delivered in the driving waveforms3102, 3104, and 3106 of FIG. 31) may be at a fundamental designfrequency of the coils placed in the transmitter.

FIG. 28 is a schematic illustration of a base unit system and across-sectional view of the base unit system in accordance with examplesdescribed herein. The base unit 2802 may have a housing which defines arecess 2806. A receiver e.g. an electronic device such as camera 2804)may be placed in the recess 2806 for charging in some examples. Althoughcamera 2804 is shown in FIG. 28, generally any electronic device havinga receiver coil may be used in other examples.

A cross-sectional view of the base unit 2802 and camera 2804 is alsoshown in FIG. 28. The base unit 2802 may have a housing which, togetherwith optional cover 2814, encloses a transmitter coil 2810, circuitboard 2808, and battery 2812.

The transmitter coil 2810 and receiver coil 2816 may be implementedusing examples of transmitter and receiver coils described herein. Forexample, the transmitter coil 2810 and receiver coil 2816 may beimplemented using a magnetic material core (e.g. rod) which may beimplemented using a ferrite material, within a wire winding (e.g.stranded. Litz, and/or copper wire winding).

The circuit board 2808 may include circuitry for wireless power deliveryfrom the battery 2812, using the transmitter coil 2810, to the receivercoil 2816. Examples of circuitry described herein may be used toimplement circuitry on the circuit board 2808.

In some examples, the circuitry on the circuit board 2808 may heoptimized for wireless power delivery at a particular distance and/orrelative orientation.

The recess 2806 may be designed such that it facilitates placement of anelectronic device (e.g. Camera 2804) such that a receiver coil 2816 ofthe camera 2804 is positioned at a particular distance and with aparticular relative orientation to the transmitter coil 2810. Forexample, the camera 2804 and recess 2806 may be designed to place thereceiver coil 2816 at a distance and/or relative orientation from thetransmitter coil 2810 for which circuitry on the circuit board 2808 isoptimized for wireless power transmission.

In some examples, the recess 2806 and/or camera 2804 may include matingfeatures, such as mating features 2818, to aid in proper positioning ofthe camera 2804. For example, as shown in FIG. 28, the camera 2804 mayinclude a protrusion while the recess 2806 includes a groove sized toreceive the protrusion on the camera 2804.

FIG. 29 is a schematic illustration of a variety of transmitter andreceiver arrangements in accordance with examples described herein.Three arrangements are shown in FIG. 29—arrangement 2902, arrangement2904, and arrangement 2906.

In the arrangement 2902, receiver 2908 includes receiver coil 2910. Thetransmitter coil 2912 includes a wire winding around a portion of amagnetic material 2914. The magnetic material 2914 is shaped in aU-shape with additional portions at the top of each U arm turned backtoward the center. The receiver 2908 may be positioned for charging suchthat it is aligned between those additional portions. The U-shapedmagnetic material 2914 with additional portions at the top of each U armmay provide for strongly guided flux for charging the receiver 2908,which has a receiver coil 2910 aligned with the transmitter coil 2912.

In the arrangement 2904, receiver 2916 includes receiver coil 2918. Thetransmitter coil 2920 includes a wire winding around a portion of amagnetic material 2922. The magnetic material 2922 is shaped in aU-shape. The receiver 2916 may be positioned for charging such that itis aligned so the receiver coil 2918 is parallel to the wire-woundportion of the magnetic material 2922. The receiver 2916 may, however,not be between the U arms. The shape of the magnetic material 2922 mayaid in partially guiding flux for charging the receiver 2916.

In the arrangement 2906, receiver 2932 and receiver 2934 includereceiver coil 2930 and receiver coil 2928, respectively. The transmittercoil 2924 includes a wire winding around a portion of a magneticmaterial 2926. The magnetic material 2926 may be shaped like a rod.Receiver 2932 and receiver 2934 (and any number of other receivers) maybe positioned for charging such that they are aligned so theirrespective receiver coils are parallel with the wire-wound portion ofthe magnetic material 2926. The shape of the magnetic material 2926 mayaid in partially guiding flux for charging the receiver 2932 and thereceiver 2934.

Examples of base units and systems described herein may advantageouslybe used to provide power in some examples to certain forms of electronicwearable devices that may utilize significant amounts of power such thatit is difficult or undesirable to build the battery requirements desired(e.g. for an 8 hour day) completely into the electronic wearabledevices—for example devices worn on or about the head of a wearer.Smaller battery capacity may undesirably result in having to rechargethe electronic wearable device during the day thus causing the wearer tonot be able to utilize the electronic wearable device. By way of exampleonly, such electronic wearable devices may include, but are not limitedto body-worn hearing aids or medical devices or implantable hearing aidsor other medical implants. Example systems described herein may be usedto charge, power and/or augment additional power to the electronicwearable device by way of mobile wireless power transfer so that theform factor of the electronic wearable device need not be increased.

Accordingly, systems and base units described herein (such as thetransmitter 2602 of FIG. 26) may be used to wirelessly power electronicwearable devices that may be worn on or about a head of a user (e.g.such electronic wearable devices may be or include the receiver 2604 ofFIG. 26). The transmitter 2602 may be attached to and/or incorporated inan article worn around the neck and/or shoulders. In some examples, a.plurality of transmitters may be provided. The transmitter may beremovable, re-attachable and rechargeable in some examples. Thetransmitter can be housed within a pouch in some examples. Thetransmitter can be housed within an attachable and detachable pouch insome examples. The transmitter can be surrounded with a cushioningmaterial in some examples. The transmitter can be surrounded by abreathable material in some examples. The transmitter can be attached toand/or incorporated in a scarf in sonic examples. The transmitter can beattached to and/or incorporated in a cloth tube worn on the neck in someexamples. The transmitter can be attached to and/or incorporated in acollar in some examples. The transmitter can be attached to and/orincorporated in a vest in some examples. The transmitter can be attachedto and/or incorporated in a coat in some examples, The transmitter canbe attached to and/or incorporated in a garment worn on the shoulders insome examples. The transmitter can be attached to and/or incorporated ina shirt in some examples. The transmitter can be attached to and/orincorporated in a jacket in some examples. For example, a transmittermay be incorporate in a patch, or multiple patches, such as threepatches, and incorporated on a jacket, such as in the shoulders of thejacket or on a surface of the jacket. The transmitter may transmit at abody safe frequency.

The electronic wearable device may be a hearing aid (e.g. the receiversuch as the receiver 2604 of FIG. 26, may be mounted to and/orincorporated in a body-worn or implanted hearing aid). In otherexamples, the electronic wearable device can be another type ofelectronic device, such as a different type of medical device e.g., bodyworn, or partially or fully implanted such as an insulin pump, a cardiacmonitor, or a pacemaker as shown in FIG. 36).

The transmitter surface closest to the body of the wearer may be locatednear a metallized fabric to reflect heat and magnetic flux of thetransmitter. The transmitter surface furthest away from the body of thewearer may include vents for releasing heat from the transmitter.

FIG. 30 is a schematic illustration of transmitter placement in a jacketin accordance with examples described herein. While illustrated anddescribed with reference to a jacket, it will be understood thattransmitters according to the present disclosure may be placed in otherarticles worn by a user, such as other clothing articles (e.g., a shirt,a vest, a pant, a dress, etc.) or accessories (e.g., an eyewear, awatch, an arm band, a necklace or other jewelry, a belt, a headcovering, etc.) The jacket 3002 is shown having threetransmitters—transmitter 3004, transmitter 3006, and transmitter 3008,positioned in the collar of the jacket. Other locations, such as theshoulders, front, or back, of the jacket may be used in other examples.The transmitters in FIG. 30 are shown schematically by their transmittercoils, although the coil and electronics may be packaged in a patch.Each transmitter may be implemented using any of the transmittertechnology described herein, such as the transmitter 2602 of FIG. 26,are disposed on a jacket. Each patch may be sized for example, 100 mm×50mm×38 mm and may include fabric insulation, such as 5 mm fabricinsulation, around the patch. Each patch may be suitable for providingabout 5 Watts of power, although other amounts may be provided in otherexamples. Each transmitter may have a transmitter coil measuring 67mm×12 mm each, including a magnetic core and wire winding around themagnetic core. The transmitters may be positioned on the jacket within200 mm of a wearable electronic device (e.g. hearing aid) for anexpected 15% power transfer efficiency in this example although otherdistances and efficiencies may be achieved in other examples. The totalpower transmitted from the three patches to the hearing aid may beapproximately expected to be the root mean squared (RMS) sum of thepower transmitted from each transmitter times the efficiency, e.g., 0.15√(5²+5²+5²)=1.3 watts. A. total of 350 mA at 3.7V may be provided in thegoggle, giving a 35% duty cycle if a power need of 250 mA is assumed.Other currents, voltages, and duty cycles may be achieved in otherexamples. Each transmitter may be provided with a 1600 mA lithium ionrechargeable battery, and the patches may have an interface forrecharging the battery, which may be wired or wireless. Expecteddimensions of the transmitter in this example are 28 mm×50 mm×100 mm.Each transmitter may further include PMIC firmware that may alternateturning each transmitter ON/OFF in accordance with the powerrequirements.

From the position on the wearable article, such as the jacket 3002. inFIG. 30, the transmitters may power any of a variety of wearableelectronic devices, such as a hearing aid worn or implanted in thewearer of the jacket 3002, and/or devices such as cell phones, watches,walkie-talkies, guns, or other devices carried or worn on the arms orwaist of the wearer of the jacket. In other examples, transmitters maybe positioned in other clothing near to wear an electronic wearabledevice may be expected to be located (e.g. in a shoe for a leg- orankle-worn electronic wearable device).

Examples described herein may accordingly allow for generally any bodyworn item, (e.g. body worn unit) to serve as a wireless charging system.The body worn charging unit may detect devices that require charging,and only transmit charging power when a device is within a predetermineddistance from the body worn unit, but not necessarily physicallyattached to said body worn unit with the attachment mechanisms.

Examples described herein may find use in powering implanted devices,such as medical devices. Increasingly, electronic devices are beingimplanted within the human body. These devices can offer many benefitsfor those in which they are implanted. These devices may requireelectrical power. In most cases an implanted electrical device mayinclude a battery that has a limited life time. Once this life time isapproached, the battery must be removed and a new oneinstalled/implanted. Medical devices that may be powered by examplewireless charging systems described herein include, by way of exampleonly, deep brain neurostimulators, hearing aid implants, cochlearimplants, cardiac pace makers, cardioverter defibrillators, insulinpumps, subdermal biosensors, drug implant pumps, implantable stimulators(e.g. nerve, bladder, deep brain, spinal cord), or combinations thereof.The ongoing need for power may hamper the usefulness of these devices insome examples. There is a need to safely be able to recharge the batteryof an implanted electronic device in situ without having to reopen thesubcutaneous skin tissue layer.

FIG. 32 is a schematic illustration of a hearing aid system 3200arranged in accordance with some examples herein. The hearing aid system3200 includes a hearing aid device 3201 (or simply hearing aid 3201),which may be configured to be wirelessly powered or wirelessly chargedby a wireless power transfer unit (e.g., base unit 3801) as describedherein. The base unit 3801 may be implemented in accordance with any ofthe examples herein. For example, the base unit may be implemented inaccordance with base unit 100, 300, 1600, or another device comprising atransmitter such as transmitter 2602. The hearing aid device 3201 may bean in-the-ear hearing aid, a behind-the-ear hearing aid, an implantedhearing aid or other type of hearing aid. In the illustrated example,the hearing aid device 3201 includes a microphone 3203, an amplifier3205, and a speaker 3207. The microphone 3201 is configured to detectambient sounds (e.g., acoustic waves 3251). The microphone is configuredto convert the acoustic input 3252 (e.g., detected acoustic waves) intoelectrical signals 3253, which are transmitted to the amplifier 3205.The amplifier is operatively coupled to the microphone to receive thesignals 3253. The amplifier 3205 amplifies the signals representative ofthe detected acoustic input (re, signals 3253) and transmits theamplified signals 3255 to the speaker 3207, which then generatesacoustic output 3257 (e.g., audible sounds represented by acoustic waves3258) that that can be provided to the user. The hearing aid 3201 mayinclude one or more analog-to-digital and digital-to-analog signalconverters (not shown), which may be part of the overall audioprocessing circuitry 3204 of the hearing aid device 3201.

In accordance with the examples herein, the heating aid 3201 may beconfigured to receive power wirelessly. The hearing aid 3201 may includea receiver 3210 configured to receive wireless power from a transmitter,for example the transmitter of a base unit, a transmitter of a body-wornrepeater, or one or more transmitters embedded in or attached to awearable article The receiver 3210 may be implemented in accordance withany of the examples herein. For example, the receiver may include atleast one receiving or receiver coil which is configured to receiveradio wave signals in given frequency ranges. In some examples, thereceiver may include a telecoil, a communication coil, or both, any oneof which may be configured as multi-function receiving coils (e.g., towirelessly receive audio signals, power signals, as well as performcommunication functions such as reception and/or transmission of data).

In some examples, the receiver may be integrated with a telecoil (orT-coil) of the hearing aid device 3201. In some examples, the telecoilof the hearing aid may provide the audio function of a typical telecoilas well as functionality for wireless power reception. In otherexamples, as discussed further below with reference to FIG. 38, thehearing aid may additionally or alternatively include a communicationcoil which may also be configured to provide the audio function (e.g.,receive audio signals) as well as a wireless power reception function(e.g., receive power signals).

In the illustrated example in FIG. 32, the hearing aid device 3201includes a telecoil 3212, which is configured to pick up radio wavesignals (also referred to as RF signals) when the telecoil is providedin a magnetic field, such as the magnetic field generated by a hearingloop, an infrared system, or an FM transmitter. As shown in FIG. 32, thetelecoil 3212 is configured to pick up radio frequency (RF) signals 3261in a first frequency range F1. The telecoil 3212 may be furtherconfigured to pick up radio frequency (RF) signals 3263 in a secondfrequency range F2. The telecoil may generate and transmit first signals3264-1 responsive to the signals 3261 in the first frequency range. Thesignals 3264-1 may be coupled to a switching circuit 3242. The telecoilmay also generate and transmit second signals 3264-2 responsive to thesignals 3263 in a second frequency range. The signals 3264-2 may becoupled to the switching circuit.

The switching circuit 3242, may be integrated with a hearing aidcontroller 3240, may be configured to isolate the 3264-1 from thesignals 3264-2. The switching circuit may be configured to couple thesignals 3264-1 to the audio processing circuitry 3204 for generatingacoustic output representative of the first signals 3261-1. Thus, thesignals 3261-1 may also be referred to as audio signals and the firstfrequency range may be referred to as audio frequency range. Typically,the acoustic signals include RF signals having a frequency below 10 kHz.The audio frequency range may thus include signals with frequenciesbetween 1 Hz and 10 KHz.

The switching circuit 3242 may be configured to couple the signals3264-2 to the power supply circuitry 3230 for use in powering componentsof the hearing aid 3201. That is, the power supply circuitry 3230 maygenerate power responsive to the second signals 3264-1. In someexamples, the power supply circuitry 3230 may include a rechargeablebattery 3232 and may be configured to recharge the battery 3232responsive to the second signals 3264. Thus, in this manner, the signals3263 received up by the telecoil 3212 may be used to wirelessly rechargethe hearing aid 3201. In some examples, the power supply circuitry 3230may directly power the hearing aid device without storing power. In someexamples, the power supply circuitry 3230 may include one or morecapacitors which may provide for temporary storage of power.

The second frequency range F2 may include signals having a frequency of10 KHz and above. The use of signals in different frequency ranges mayreduce the risk of interference between the audio and power functions ofthe telecoil. In some examples, the second frequency range F2 mayinclude signals in frequencies that are significantly higher than theaudio frequencies, such that isolation of the signals in the F2 rangecan be easily made and thus interference with normal operation of theaudio functions of the telecoil may be substantially avoided. In someexamples, the second frequency range F2 may include frequencies above100 KHz.

To separate the signals in the F1 range from those in the F2 range, thesignals 3264-1, 3264-2 from the telecoil may be passed to the switchingcircuit 3242, which may be configured to isolate signals inpredetermined ranges of frequencies. The switching circuit 3242 may beconfigured to direct signals having frequencies in the first range (F1range) towards the audio processing circuitry 3204 and to direct signalshaving frequencies in the second range (F2 range) towards the powersupply circuitry 3230. The switching circuit 3242 may include one ormore filters 3244. For example, the signals from the telecoil (e.g.,signals 3264-1, 3264-2) may be passed through a high-pass filter and alow-pass filter connected in parallel. An example of a high-pass filteris shown in FIG. 33. The high-pass filter may be configured pass thehigher frequency signals (e.g., signals 3264-2) and attenuate signalsbelow a cutoff frequency (e.g., signals below the minimum value of thepower frequency range). The low-pass filter may be configured pass thelower frequency signals (e.g., signals 3264-1) and attenuate signalsabove a cutoff frequency (e.g., signals above the maximum value of theaudio frequency range). The higher frequency signals isolated by theswitching circuit 3242 may then be coupled to the power supply circuitryfor power generation (e.g., for charging the battery 3232). The lowerfrequency signals isolated by the switching circuit 3242 may then becoupled to the audio processing circuitry for audio generation (e.g.,for providing the acoustic output 3257).

In some examples, the receiver 3210 of the hearing aid device 3201 mayinclude a separate receiving coil in addition to or instead of thetelecoil, which is configured to receive wireless power signals (e.g.,signals 3263 in the second frequency range). The receiver may include acoil having a rod-shaped magnetic core (e.g. ferrite or otherferromagnetic material) wound with a wire winding (e.g. copper wire, orLitz wire). In some examples, the receiver 3210 may also be configuredto receive and/or transmit data 3265 (e.g., configuration data). Thehearing aid 3201 may include a storage device 3238 (e.g., non-volatilememory) operatively connected to the receiver for storing dataassociated with the hearing aid device. The memory may also storeprogramming (e.g., computer executable instructions, which may be usedby a controller 3240 to control functions of the hearing aid device3201.

A base unit 3801 may be provided in proximity to the hearing aid device,for example, positioned in a shirt pocket of the user, or otherwiseattached to and/or worn by the user such as on a belt, a necklace, oreyewear worn by the user. Unlike existing wireless charging deviceswhich typically require the device being charged to be placed and remaininto, onto or in a specific location with respect to the charging devicewhile charging, the base unit 3801 may be mechanically decoupled andthus movable relative to the hearing aid device during wireless powertransfer. In some examples, the base unit 3801 may be distance separatedfrom the hearing aid, for example by 5 mm, 10 mm, 20 mm, 50 mm, 100 mm,200 mm or a greater distance. The base unit 3801 may be implementedusing any examples of base units described herein, and may include atransmitter including transmitter coil 3803. The base unit 3801 mayprovide power to the hearing aid device 3201 to power or charge thebattery of the hearing aid device by coupling power from the transmittercoil 3803 to the receiver 3201 (e.g., to the telecoil 3212 or otherreceiving coil).

Generally, any base unit and/or transmitter and/or transmitter coildescribed herein may be utilized to provide wireless power to animplanted electronic device. Generally, any receiver and/or receivercoil described herein may be incorporated in and/or attached to animplanted electronic device for receipt of wireless power which may, forexample, recharge a battery of the implanted electronic device.

While the example in FIG. 32 is described with reference to a wornhearing aid, a similar configuration may be used to implement animplanted hearing device such as COCHLEAR brand hearing implant oranother type of implantable medical device such as a cardiac pacemakeror implantable defibrillator, an example of which is described furtherwith reference to FIG. 36.

In some embodiment the power transfer functions can be turned off duringthe normal use of the telecoil (e.g., when receiving audio signals).This can be done with intelligent communication between the base unitand the hearing aid or it can be done by keeping the magnetic fieldstrength of the power transmitter weak enough that charging signals canonly be picked up near the base unit when the hearing aid is not in useand is removed for the evening. In still other embodiments a switch canbe placed the base unit, to manually disable the broadcasting ofwireless power, and/or the hearing aid. In the case of a switch on thehearing aid, the switch can default into a position in which thetelecoil is only connected to the power supply circuitry when thehearing aid is placed in close proximity to the base unit (e.g., afraction, such as 50%, 25%, or less, of the available charging range ofthe base unit). In this manner, the telecoil may be set to only operateas an audio pick up device when the hearing aid is in use (i.e., worn bythe user) with the telecoil switching to charging mode when the hearingaid is not in use not worn by the user but placed near the base unit forcharging).

As described, the telecoil may include a ferrite core. A telecoil with aferrite core may be suitable for wireless power transfer due to thecore's high magnetic permeability. In other examples, other materialscan be used for the core such as, by way of example only, ferrite, mumetal, Vitroperm 500F, or another high permeability metal. In certainembodiments the transmitter coil core can be made of ferrite and thereceiver coil core can be made of a different magnetic metal material.In other embodiments the transmitter coil core and the receiver coilcore can be made of the same magnetic metal material. In still otherembodiments the receiver coil core can be made out of ferrite and thetransmitter coil core can be made of a different magnetic metalmaterial. The wire winding material can be that, by way of example only,of a copper wire, wire strands of copper or other conductive metals,Litz, or other suitable conductive wire.

Systems according to further examples may include intermediate baseunits, as shown for example in FIGS. 34-35. FIG. 34 shows a system 3400which includes an in-the-ear hearing aid device 3401 and an intermediatebase unit 3405. The hearing aid device 3401 may be implemented inaccordance with any of the examples herein. For example, the hearing aiddevice 3201 may be used to implement hearing aid device 3401. Theintermediate base unit 3405 may be implemented in accordance with any ofthe examples of power transmitting devices described herein. Forexample, the base unit 100, any of the transmitters 2602, 2702, 2712,2720, and 2728, or body-worn repeater 2304 may be used to implementintermediate base unit 3405. The intermediate base unit 3405 may or maynot include a power storage component (e. g. a battery).

In some examples, the intermediate base unit 3405 may be configured toonly retransmit power, without storing it onboard the intermediate baseunit 3405, from another base unit 3407 which may store power for examplein a battery 3408. The base unit 3407 may include a transmitting coil3409 which is configured to couple power to a receiving coil in theintermediate base unit 3405, which then retransmits the power to areceiving coil in the hearing aid device 3401 (e.g., a telecoil of thehearing aid device 3401). The base unit 3407 may be implemented inaccordance with any of the examples of power transmitting devicesdescribed herein, such as the base unit 100, or any of the transmitters2602, 2702, 2712, 2720, and 2728. In the example in FIG. 34, componentsof the intermediate base unit 3405 is body-worn (e.g., arranged in ahousing at least a portion of which is positionable over and/or behindthe user's ear similar to an ear hook type headphone.

In the further examples, as shown in FIGS. 35A and 35B, the intermediatebase unit 3405 is attachable to a body-worn accessory such as eyewear.In the examples in FIGS. 35A and 35B, components of the intermediatebase unit 3405 are arranged in a housing which is attachable, in somecase removably attachable, to an eyewear frame, for example to thetemple of the eyewear. The intermediate base unit 3405 in FIG. 35A isoperatively associated with a behind-the-ear hearing aid 3401, while theintermediate base unit 3405 in FIG. 35B is operatively associated withan in-the-ear hearing aid 3401. In each of these examples, theintermediate base unit 3405 may be configured to couple power receivedfrom another base unit (such as base unit 3407) to the hearing aid.According to some examples herein, the intermediate base unit 3405 maythus improve system performance and/or relax requirements on base unitsand/or wearable electronic devices described herein.

By positioning the intermediate base unit between a base unit and ahearing aid or other medical assistance device (e.g., such that adistance between the body-worn repeater and the wearable electronicdevice is less than a distance between the base unit and the wearableelectronic device), range of the overall system may be improved. Forexample, it may be disadvantageous, impractical, or impossible toprovide power from the base unit over the entire distance between thebase unit and the hearing aid or other medical assistance device.However, placement of an intermediate base unit may allow the wirelesspower to be relayed from the main base unit to the hearing aid or othermedical assistance device.

Moreover, intermediate base unit may improve efficiency of wirelesspower transfer by reducing orientation dependencies between a base unitand a hearing aid or other medical assistance device. For example, baseunits described herein may include a magnetic core and may haveincreased efficiency with a receiving device when in a particularorientation, or range of orientations. By placing an intermediate baseunit to mediate wireless power transfer, one orientation is providedbetween the base unit and the intermediate base unit, and anotherbetween the intermediate base unit and the a hearing aid or othermedical assistance device. Accordingly, the orientation between the baseunit and the intermediate base unit may be closer aligned than theorientation between the base unit and the hearing aid or other medicalassistance device. The orientation between the intermediate base unitand the hearing aid or other medical assistance device may be closeraligned than the orientation between the base unit and the hearing aidor other medical assistance device.

In some examples, use of intermediate base units as described herein mayreduce complexity that may otherwise be required when using a singlebase unit. For example, one intermediate base unit may provide wirelesspower to a plurality of wearable electronic devices (e.g., a pluralityof medical assistance devices), and certain of the wearable electronicdevices may have different carrier frequency and/or modulation (e.g. fordata transfer) parameters. Examples of intermediate base units describedherein may be tuned (e.g. using a controller or other processor(s)forming part of the intermediate base unit) to have a different carrierfrequency and/or different frequency modulation based on the identitiesof wearable electronic devices with which the intermediate base unit iscommunicating. In this manner, a base unit may provide power to anintermediate base unit using one frequency and/or modulation scheme, andthe intermediate base unit may utilize multiple frequencies and/ormodulation schemes to communicate with different wearable electronicdevices. In some examples, this may relieve the base unit of the need toitself provide different frequencies and/or modulation schemes.

In some examples, the transmitting and/or receiving coils provided in abase unit and a wearable electronic device, respectively, may haveconstruction which includes a single magnetic core that has separatewire windings for different functions. In the case of the transmittingcoil, different windings may be used to transmit signals at differentfrequencies and/or modulation schemes, for example for communicatingwith different electronic devices. In the case of the receiving coil onthe wearable electronic device, the different windings can providedifferent functions, such as power signals reception and audio signalsreception.

FIG. 37 is a schematic illustration of a hearing aid system 3700arranged in accordance with some examples herein. The hearing aid system3700 includes a hearing aid device 3201′ (or simply hearing aid 3201′),which may be configured to be wirelessly powered or wirelessly chargedby a wireless power transfer unit as described herein (e.g., base unitor another device comprising a transmitter, such as transmitter 2602,not shown in this Figure). The hearing aid device 3201′ may include oneor more of the components of hearing aid 3201. For example, the hearingaid device 3201′ includes a microphone 3203, an amplifier 3205, and aspeaker 3207. The microphone 3201 is configured to detect acoustic waves3251. The microphone 3201 is configured to convert the acoustic input3252 (e.g., detected acoustic waves) into electrical signals 3253, whichare transmitted to the amplifier 3205. The amplifier 3205 is operativelycoupled to the microphone 3201 to receive the signals 3253. Theamplifier 3205 amplifies the signals representative of the detectedacoustic input (i.e., signals 3253) and transmits the amplified signals3255 to the speaker 3207, which then generates acoustic output 3257(e.g., audible sounds represented by acoustic waves 3258) that that canbe provided to the user. The hearing aid 3201′ may includeanalog-to-digital signal converter and a digital-to-analog signalconverter (not shown), which may be part of the overall audio processingcircuitry 3204 of the hearing aid device 3201.

In accordance with the examples herein, the hearing aid 3201′ may beconfigured to receive power wirelessly. The hearing aid 3201′ mayinclude a receiver 3210′ configured to receive wireless power from atransmitter, for example the transmitter of a base unit (not shown). Thereceiver 3210′ may be implemented in accordance with any of the examplesherein. For example, the receiver 3210′ may include a receiving coilwhich is configured to receive radio wave signals in given frequencyranges. The receiving coil may be a specially adapted telecoil which isconfigured to provide both the functions of audio signals reception andwireless power reception.

As shown in FIG. 37, the hearing aid 3201′ may include a telecoil 3212′which is configured to receive both audio and power signals. Thetelecoil 3212′ may include a core 3214 (e.g., a ferrite or othermagnetic material core) and wire windings. A first set of wire windings(e.g., wire winding 3215) wound around the core 3214 may be configuredto tune the telecoil 3212′ for audio pick up (e.g., for detectingsignals 3261 in the first frequency range F1 and generatingcorresponding signals 3264-1), while a second set of wire windings(e.g., wire winding 3217) would around the core 3214 may be may beconfigured to tune the telecoil 3212′ for power reception (e.g., fordetecting signals 3263 in the second frequency range F2 and generatingcorresponding signals 3264-2). In some examples, the respective firstand second windings may be directly wired to dedicated circuitry for therespective first and second functions. That is, in the example in FIG.37, the windings 3215 for the audio function may be wired directly tothe audio processing circuitry 3204, while the windings 3217 for thepower function may be wired directly to the power supply circuitry 3230,which may or may not include a power storage device (e.g., battery3242). While two sets of windings are shown in the illustratedembodiment, it will be understood that in other embodiments, thereceiving coil may include a greater number of separate windings, one ormore of which may be associated with a different function. For example,the receiving coil may include three sets of windings, each of which maybe associated with one of three different functions (e.g., audio, power,or data transfer). In other examples, the receiving coil may have aplurality of windings (e.g., three, four, five or more sets of windings)and two or more of the sets of windings may be associated with the samefunction.

In some examples, the receiver 3210′ of the hearing aid device 3201′ mayinclude a separate receiving coil in addition to or instead of thetelecoil 3212′, which is configured to receive wireless power signals(e.g., signals 3263 in the second frequency range). In some examples,the receiver 3210′ may also be configured to receive and/or transmitdata 3265 (e.g., configuration and/or calibration data for the hearingaid 3201′). The hearing aid 3201′ may include a storage device 3238(e.g., non-volatile memory) operatively connected to the receiver, suchas via one or more controller 3240′. The storage device 3238 may storedata received or data generated by the hearing aid 3201′ as well asprogramming (e.g., computer executable instructions, which may be usedby the controller 3240 to control functions of the hearing aid device3201′). In some examples, the separate windings may be wound in aninterleaved manner along the length of the core. In some examples, theseparate windings may be wound in an overlaid manner, e.g., with one setwound closest to the surface of the core, a second set over the firstset, and so on. In vet further examples, the separate sets of windingsmay be wound in an adjacent matter, e.g., with each set wound on thecore but spanning only a portion of the length of the core. Otherarrangements may be used in other examples.

Systems are provided for safely charging an implanted electronic device.The electronic device may be located beneath the subcutaneous tissue,and may include a receiver coil. A transmitter including a transmittercoil may be located external to the subcutaneous tissue. The coil of thetransmitter coil and the receiver coil may be weakly wirelessly coupledby way of resonance. The resonance can be that of a weak resonance. Theweak resonance can have a Q factor of less than 100, The weak resonancecan have a Q factor of less than 75. The weak resonance can have a Qfactor of less than 50. The system can utilize a guided flux. The systemcan utilize a partially guided flux. The receiver can be maintainedwithin a 2 degree C. range of its normal in situ resting temperature.The system can maintain the receiver to be within a 2 degree C. range ofits normal in situ resting temperature. The receiver coil, transmittercoil, or both can be implemented using a magnetic core. The receivercoil, transmitter coil, or both can be include a wire winding around thecore and the core can be implemented using a ferrite member. The wirewinding of the transmitter coil, receiver coil, or both can beimplemented using copper wire. The wire winding of the transmitter coil,receiver coil, or both can be implemented using Litz wire. The implantedelectrical device can include a titanium outer skin. The transmitter cantransmit a frequency within the range of 75 kHz to 150 kHz to thereceiver of the electronic device. The transmitter can transmit afrequency within the range of 100 kHz to 130 kHz to the receiver of theelectronic device. The transmitter can transmit a frequency within therange of 125 kHz to the receiver of the electronic device. Thetransmitter can be housed in a cloth patch which can be attached to anarticle of clothing. The transmitter can be attached to hat. Thetransmitter can be attached to a shirt. The transmitter can be attachedto pants. The transmitter be attached to a coat. The transmitter can beattached to a belt. The transmitter can be attached to a band aid. Thetransmitter can be attached to an adhesive patch. The transmitter can berecharged. The transmitter can be detached and reattached.

FIG. 36 is a schematic illustration of a wirelessly powered implantable:device arranged in accordance with examples described herein. The systemshown in FIG. 36 includes a defibrillator having an implanted controller3602 beneath a user's skin and debribrillator lead 3612 positioned inthe user's heart. The implanted controller 3602 may be provided with areceiver in accordance with examples described herein, includingreceiver coil 3604, which may have a rod-shaped magnetic core (e.g.ferrite) wound with a wire winding (e.g. Litz wire). A base unit 3610may be provided which may, for example, be positioned in a shirt pocket3608 of the user, or otherwise attached to and/or worn by the user. Thebase unit 3610 may be implemented using any examples of base unitsdescribed herein, and may include a transmitter including transmittercoil 3606. During operation, the base unit 3610 may provide power to theimplanted controller 3602 by coupling power from the transmitter coil3606 to the receiver coil 3604.

Generally, any base unit and/or transmitter and/or transmitter coildescribed herein may be utilized to provide wireless power to animplanted electronic device. Generally, any receiver and/or receivercoil described herein may be incorporated in and/or attached to animplanted electronic device for receipt of wireless power which may, forexample, recharge a battery of the implanted electronic device.

An example implantable device may have a battery implantedsubcutaneously which may have a 100 mAH current capacity. It may have anominal charged capacity of 370 mW-hr. It may take 1-2 hours to rechargeand have a 10 year expected lifetime. Other implantable deviceparameters may be used in other examples. The implantable device mayinclude a receiver coil, examples of which have been described herein.The receiver coil may have a magnetic core and a wire winding woundaround the magnetic core. In some examples, the receiver coil may havedimensions of 7 mm×2 mm×2 mm, however, other dimensions may be used inother examples. The receiver coil may generally be smaller than thetransmitter coil. The implanted device may include a 100 mAH batterywith maximum thickness of 4 mm with 10+ year functional lifespan. Otherspecifics may be used in other examples. Example implantable electronicdevice may utilize solid state thin film Lithium batteries, where lossof capacity may remain less than 50% after 1000 cycles.

Wireless power charging systems described herein may be used to charge asubcutaneously implanted battery safely and wirelessly. A rechargingunit (e.g. a base unit described herein) may be positioned in a locationexternal to the user but proximate to the implanted device. In someexamples, the transmitter coil of a base unit may be provided 50-100 mmfrom an expected location of a receiver coil in an implanted medicaldevice. For example, a base unit may be mounted on an eyeglass frame foruse in charging a hearing aid or other in-head device. The base unit(e.g. transmitter) may include an internal battery that may providepower for wireless power delivery through the transmit coil which maycharge the battery in an implantable electronic device. The powerdelivery may occur through skin or other tissue. The transmitterinternal battery may be recharged wirelessly when not attached toeyewear, or when placed in proximity to another base unit or chargingdevice (e.g. body-worn repeater).

In some examples, a base unit may be incorporated in a patch or otheraccessory to be worn by an implanted device user or attached to orincorporate in clothing of the implanted device user. In some examples,a coil length of a transmitter coil may be 50 mm, however other lengthsmay also be used. In some examples, the base unit may provide 1 watt ofpower and may limit temperature rise to less than 2° C.

In some examples, a base unit may be positioned under and/or inside apillow. The transmitter in the base unit may recharge a battery in animplantable device (e.g. in a user's head) as the user sleeps overnight.The transmitter internal battery may be plugged into USB or AC powersupply to be recharged during the day.

In some examples, a transmitter may be built into small wearable patch.The transmitter may recharges an implanted battery with patch worn inclothing—such as attached using Velcro® to a hat. The transmitterinternal battery may be plugged into USB or AC power supply to berecharged.

An example base unit may recharge a subcutaneously implanted batterycontained in a hermetically sealed titanium housing with less than 20%loss of efficiency in some examples, less than 10% in some examplesthrough a 100 micron titanium sheet. Generally, expected wireless powertransfer efficiency between a base unit and an implantable electronicdevice may be 10-20% in some examples, although other efficiencies maybe attained in other examples. A power transfer rate of 100-200 mW maybe attained in some examples. An expected recharging time of 1-2 hoursmay be attained in some examples.

FIG. 38 is a schematic illustration of a hearing aid system 3800illustrating sonic of the components of yet another hearing aid 3801 inaccordance with examples of the present disclosure. The hearing aid 3801may include one or more of the components of any of the hearing aidsdescribed herein, for examples components of hearing aid 3201 or 3201′.Some of the components of the hearing aid have been omitted in theillustration so as not to obfuscate the features described herein.

In the embodiment shown in FIG. 38, the hearing aid 3801 includes acommunication coil 3814, a power management circuit 3820, a rechargeablebattery 3832 and an optional telecoil 3812. In some examples, a singlecoil may be used (e.g., a communication coil) which is capable of atleast receiving audio frequency signals and transmitting audio frequencysignals for performing audio functions of the hearing aid, and receivinga wireless power frequency signals for charging the hearing aid.

In the embodiment in FIG. 38, the telecoil 3812, similar to telecoil3212, may be configured to receive both audio and power signals. Thereceived audio signals are coupled to audio processing circuitry (notshown in this figure) for generating audio outputs. The communicationcoil 3814 may be configured as a. multi-function coil, for example withthe capability of receiving both audio and power signals. In someexamples, the communication coil 3814 may provide additionalfunctionality such as data (e.g., image, audio, etc.) reception andtransmission. The communication coil may be configured to provide thefunction of wireless communication to another computing system (e.g., apersonal computer, a base unit) external to the hearing aid, whichcomputing system may be used to program the hearing aid.

In some examples, the telecoil may be omitted and the audio, power, andother communication functions may be provided by the communication coil.

The communication coil 3814 and/or telecoil 3812 are connected to thepower managed circuit 3820. The power management circuit 3820 andbattery 3832 may be part of the power supply circuitry of the hearingaid. The power management circuit may isolate the wireless power signalsreceived by the receiving coil (e.g., the communication coil 3814 and/orthe telecoil 3812) and may couple those signals to the battery forrecharging the battery. In some examples, the power management circuit3820 may include a switch circuit which configured to isolate thereceiving coil from the audio processing circuitry. The switch circuitmay include a resistor-capacitor circuit (RC circuit) or a filter (e.g.,a high-pass filter, a band-pass filter or the like), which may decouplesignals received by the coil (e.g., telecoil or communication coil)above a certain frequency (e.g., above the upper bound of the audiofrequency F1) from the audio processing circuitry. In this manner,interference with the audio function provided by either coil may beavoided. Any of the coils (e.g., telecoil 3812, communication coil 3814)be implemented using a core of a magnetic material (e.g. ferrite) withone or more wire windings (e.g. stranded wire, Litz wire, copper wire,or combinations thereof) wound around the core in accordance with any ofthe examples herein.

The above detailed description of examples is not intended to beexhaustive or to limit the method and system for wireless power transferto the precise form disclosed above. While specific embodiments of, andexamples for, the method and systems for wireless power transfer aredescribed above for illustrative purposes, various equivalentmodifications are possible within the scope of the system, as thoseskilled in the art will recognize. For example, while processes orblocks are presented in a given order, alternative embodiments mayperform routines having operations, or employ systems having blocks, ina different order, and some processes or blocks may be deleted, moved,added, subdivided, combined, and/or modified. While processes or blocksare at times shown as being performed in series, these processes orblocks may instead be performed in parallel, or may be performed atdifferent times. It will be further appreciated that one or morecomponents of base units, electronic devices, or systems in accordancewith specific examples may be used in combination with any of thecomponents of base units, electronic devices, or systems of any of theexamples described herein.

1. A hearing aid system comprising: a hearing aid comprising: amicrophone configured to detect ambient sounds; audio processingcircuitry including an amplifier operatively coupled to the microphoneto receive signals corresponding to the ambient sounds and amplify thesignals, and a speaker configured to receive the amplified signals andgenerate an amplified sound corresponding to the amplified signal; powersupply circuitry configured to power the microphone, the amplifier, andthe speaker; a receiver comprising at least one coil operatively coupledto the audio processing circuitry and the power supply circuit, whereinthe at least one coil comprises a magnetic metal core with a wirewinding, and wherein the at least one coil is configured to receivewireless signals; and a switching circuit configured to generate firstsignals responsive to wireless signals in a first frequency range andcouple the first signals to the audio processing circuitry and furtherconfigured to generate second signals responsive to wireless signals ina second frequency range and couple the second signals to the powersupply circuitry.
 2. The system of claim 1, wherein the at least onecoil comprises a telecoil, a communication coil, or a combination of thetwo.
 3. The system of claim 1, wherein the second frequency rangeincludes signals having higher frequencies than signals in the firstfrequency range.
 4. The system of claim 3, wherein the first frequencyrange includes signals having a frequency of 10 KHz or below and whereinthe second frequency range includes signals having a frequency greaterthan 10 KHz.
 5. The system of claim 4, wherein the second frequencyrange includes signals having a frequency above 100 KHz.
 6. The systemof claim 1, wherein the switching circuit includes a filter configuredto isolate the first signals from the second signals.
 7. The system ofclaim 6, wherein the filter comprises a low-pass filter configured todirect the first signals to the audio processing circuitry and ahigh-pass filter configured to direct the second signals to the powersupply circuitry.
 8. The system of claim 1, wherein the power supplycircuitry comprises a battery, and wherein power supply circuitry isconfigured to recharge the battery responsive to the second signals. 9.The system of claim 1, wherein the at least one coil is furtherconfigured to receive data, transmit data, or both, and wherein thehearing aid further comprises memory for storing the data.
 10. Thesystem of claim 1, wherein the magnetic metal core is a ferrite core.11. The system of claim 1, further comprising a base unit that comprisesa transmitter configured to transmit radio signals in the secondfrequency range, and wherein: the transmitter of the base unit comprisesa transmitter coil having a transmitter impedance; the at least one coilof the receiver has a receiver impedance; and the transmitter impedanceand the receiver impedance are optimally matched for: a particulardistance separation between the transmitter and the receiver, andnon-optimized for all other separation distances; or a particularrelative orientation between the transmitter and the receiver, andnon-optimized for all other relative orientations.
 12. The system ofclaim 11, wherein transmitter impedance and the receiver impedance areoptimally matched for at least two particular distance separationsbetween the transmitter and the receiver, and non-optimized for allother separation distances.
 13. The system of claim 12, wherein thetransmitter coil comprises a magnetic metal core.
 14. The system ofclaim 13, wherein the core of the transmitter has a volume that is 10times or larger than a volume of the core of the telecoil.
 15. Thesystem of claim 13, wherein a wire winding of the transmitter coil has awinding length that is 10 times or larger than a winding length of thewire winding of the telecoil.
 16. The system of claim 11, wherein thesystem is a weak resonant system having a Q value below
 100. 17. Thesystem of claim 11, wherein the transmitter is configured to transmitwireless power at a frequency in a range of 100 kHz to 200 kHz.
 18. Thesystem of claim 11, wherein the transmitter is configured to transmitwireless power at a frequency within a range of 125 kHz+/−5 kHz.
 19. Thesystem of claim 11, wherein the transmitter is configured to transmitwireless power at a frequency within a range of 6.75 MHz+/−5 MHz. 20.The system of claim 11, wherein the base unit is further configured totransmit data to the hearing aid.
 21. The system of claim 11, whereinthe base unit is a first base unit devoid of a battery, and wherein thesystem further comprises a second base unit including a battery, thesecond base unit configured to couple power wirelessly to the first baseunit using a different frequency range or modulation scheme that thefrequency range or modulation scheme used when coupling signals betweenthe first base unit the hearing aid.